The Impact of Bariatric Surgery on the Development and Progression of Dermatologic Diseases: A Narrative Review

Abstract

Obesity is a major global health concern characterized by excessive fat accumulation, which significantly increases the risk of numerous comorbidities. While lifestyle modifications and pharmacotherapy are commonly employed, bariatric surgery is recognized as a highly effective treatment option. These procedures alter gastrointestinal anatomy, restricting food intake and modifying nutrient absorption, thereby reducing hunger and increasing satiety. Beyond weight reduction, bariatric surgery can improve or resolve obesity-related conditions, including type 2 diabetes, hypertension, sleep apnea, and dyslipidemia. In addition to obesity, patients undergoing bariatric surgery frequently present with diverse skin disorders, such as hidradenitis suppurativa, psoriasis, necrobiosis lipoidica, skin tags, acanthosis nigricans, striae, keratosis pilaris, hyperhidrosis, plantar hyperkeratosis, intertrigo, pseudoacanthosis nigricans, lymphedema, bacterial infections, and confluent and reticulated papillomatosis. Bariatric surgery has been reported to improve or resolve conditions such as acanthosis nigricans, confluent and reticulated papillomatosis, necrobiosis lipoidica, hidradenitis suppurativa, psoriasis, hirsutism, skin tags, intertrigo, keratosis pilaris, and pebble fingers. Conversely, it may precipitate or exacerbate other conditions, including xeroderma, sporotrichosis, prurigo pigmentosa, bowel-associated dermatitis–arthritis syndrome, pellagra, disseminated intravascular coagulation, purpura, vasculitis, panniculitis, and alopecia. The relationship between obesity, weight loss, and skin health in patients undergoing bariatric surgery is complex, involving mechanisms such as inflammation, hormonal alterations, and mechanical stress on the skin. This study aims to investigate the effects of bariatric surgery on the progression and development of skin disorders, evaluating both potential improvements and the emergence of new conditions postoperatively. In summary, bariatric surgery exerts multifaceted and sometimes conflicting effects on skin health.

Key Summary Points

Obesity is a major global health concern, associated with numerous comorbidities.

Bariatric surgery not only promotes weight loss but also effectively improves or resolves obesity-related conditions, including type 2 diabetes, hypertension, sleep apnea, and dyslipidemia.

Patients undergoing bariatric surgery frequently experience multiple dermatologic conditions.

Bariatric surgery exerts a multifaceted impact on the skin, producing both beneficial and adverse effects.

Introduction

Obesity is a multifactorial chronic disease characterized by excessive adipose tissue accumulation and associated with substantial morbidity and mortality. It is not merely an aesthetic concern but a serious medical condition that markedly increases the risk of type 2 diabetes mellitus (T2DM), cardiovascular disease, hypertension (HTN), dyslipidemia, non-alcoholic fatty liver disease, obstructive sleep apnea, and certain malignancies [1]. The World Health Organization (WHO) defines obesity using body mass index (BMI), with a BMI ≥ 30 kg/m² considered diagnostic. Obesity is further categorized into class I (BMI 30–34.9 kg/m²), class II (BMI 35–39.9 kg/m²), and class III (BMI ≥ 40 kg/m²), the last of which is often referred to as severe or morbid obesity. Overweight is defined as a BMI ≥ 25 kg/m² [2]. The prevalence of obesity continues to rise worldwide. In 2016, an estimated 671 million adults were obese, while 1.3 billion were overweight. Childhood obesity is of particular concern, with approximately 50 million girls and 74 million boys classified as obese in 2016 [3]. These figures highlight the magnitude of obesity as a global public health crisis. Management of obesity is critical for reducing the burden of associated comorbidities and improving quality of life. Evidence-based strategies include dietary modification, increased physical activity, and behavioral therapy, typically delivered within a structured lifestyle intervention program.

In addition to physical comorbidities, obesity is frequently associated with psychological disorders such as depression and anxiety, which further impair quality of life and complicate disease management. Addressing these mental health concerns is therefore an integral component of comprehensive obesity care. Pharmacologic therapy may be considered as an adjunct to lifestyle modification for weight reduction or long-term weight management. Available agents act through different mechanisms, including appetite suppression, inhibition of fat absorption, or modulation of hormonal pathways involved in satiety. Liraglutide, a glucagon-like peptide 1 (GLP-1) receptor agonist, enhances satiety and reduces caloric intake by mimicking endogenous incretin signaling. Orlistat, a gastrointestinal lipase inhibitor, reduces intestinal fat absorption by blocking enzymatic hydrolysis of dietary triglycerides, thereby lowering caloric intake without directly influencing appetite [4].

Bariatric surgery (BS), also referred to as metabolic or weight-loss surgery, is the most effective treatment for severe obesity when conservative measures fail. These procedures promote weight reduction by restricting gastric volume and/or bypassing portions of the small intestine, thereby reducing caloric intake and altering nutrient absorption. In addition to substantial and sustained weight loss, bariatric surgery has been shown to improve or resolve multiple obesity-related comorbidities.

The three most commonly performed BS procedures are Roux-en-Y gastric bypass (RYGB), adjustable gastric banding (AGB), and sleeve gastrectomy (SG). RYGB involves creating a small gastric pouch and bypassing a significant segment of the stomach and proximal small intestine, leading to both restriction and malabsorption. AGB employs a silicone band placed around the proximal stomach to create a small pouch, restricting food intake. SG entails resection of approximately 80% of the stomach, leaving a tubular gastric “sleeve” that limits intake and modulates gut hormone secretion. Candidacy for bariatric surgery is generally based on BMI thresholds. Current criteria include a BMI ≥ 40 kg/m², a BMI ≥ 35 kg/m² with at least one major obesity-related comorbidity (e.g., type 2 diabetes, HTN, obstructive sleep apnea, cardiovascular disease, osteoarthritis, non-alcoholic fatty liver disease), or in some cases, a BMI ≥ 30 kg/m² with uncontrolled type 2 diabetes [5]. Despite its benefits, bariatric surgery carries potential risks. Procedures involving intestinal bypass, such as RYGB, can impair calcium and vitamin D absorption, predisposing patients to bone loss, reduced bone mineral density, and increased fracture risk [6]. Nevertheless, when compared with intensive lifestyle interventions—which typically yield 5–8% weight loss and modest improvements in cardiovascular risk factors—bariatric surgery is associated with significantly greater weight reduction and medium- to long-term remission of type 2 diabetes, dyslipidemia, and HTN [7].

Obesity contributes to a wide range of cutaneous manifestations through multiple mechanisms, including impairment of the skin barrier, increased transepidermal water loss, xerosis, and erythema. Barrier dysfunction also delays wound healing and predisposes patients to recurrent skin infections. In addition, obesity is associated with systemic inflammation and metabolic dysregulation, which may exacerbate chronic inflammatory dermatoses such as psoriasis and atopic dermatitis. Common skin conditions observed in obese and overweight individuals include acanthosis nigricans, keratosis pilaris, hyperhidrosis, plantar hyperkeratosis, striae distensae, and intertrigo [8]. Given that both obesity itself and subsequent weight loss can influence dermatologic outcomes, this narrative review aims to summarize current evidence on the effects of bariatric surgery on a spectrum of skin diseases.

Materials and Methods

A comprehensive literature search was conducted in PubMed (1979–present) during the winter/spring of 2025 to identify studies evaluating the impact of bariatric surgery on dermatologic conditions. No date restrictions were applied. The search strategy included combinations of Medical Subject Headings (MeSH) and free-text terms such as “obesity and bariatric surgery,” “bariatric surgery,” “skin lesions and bariatric surgery,” “acanthosis nigricans and bariatric surgery,” “hidradenitis suppurativa and bariatric surgery,” “psoriasis and bariatric surgery,” “necrobiosis lipoidica and bariatric surgery,” “skin tags and bariatric surgery,” “hyperandrogenism and bariatric surgery,” “polycystic ovary syndrome and bariatric surgery,” “adverse effects and bariatric surgery”, and “striae and bariatric surgery.”

Exclusion criteria included non-English publications, studies with limited clinical relevance, duplicate records, and articles published in languages other than English. Both human and animal studies were initially considered for inclusion. After search results were combined and duplicates removed, titles and abstracts were independently screened by two reviewers (M.M. and H.M.) to identify relevant studies addressing the research question. Discrepancies were resolved through discussion with a third reviewer (A.C.). Full texts of eligible articles were subsequently reviewed.

Discussion

Table 1 provides a summary of studies on the effects of bariatric surgery on dermatologic diseases.

Table 1.

Summary of studies on the role of bariatric surgery in dermatologic diseases

Author	Year	Population	Key observation
Acanthosis nigricans
Fu et al. [10]	2023	319 patients with obesity  178 patients with obesity without AN  141 patients with obesity and AN	Remission of obesity-associated AN skin lesions was observed following LSG
Zhu et al. [11]	2019	65 patients with obesity  20 patients with obesity without AN  45 patients with obesity and AN	LSG significantly improved skin condition in men with obesity and AN
Zhang et al. [12]	2017	37 patients with obesity  14 patients with obesity without AN  23 patients with obesity and AN	LSG positively affected both skin condition and body composition in patients with obesity and AN
Itthipanichpong et al. [13]	2020	70 patients post-BS  46 patients with successful weight loss  24 patients with non-successful weight loss	BS can reduce prevalence of AN in neck, axillae, and inguinal regions
Confluent and reticulated papillomatosis
Krishnamoorthy et al. [14]	2021	Adolescent female with obesity	BS may serve as an effective treatment for CARP
Necrobiosis lipoidica
Bozkurt et al. [15]	2013	32-year-old woman	BS may result in complete resolution of NLD
Hidradenitis suppurativa
Canard et al. [16]	2021	12 patients with HS who have undergone BS 7 patients with HS who received NC	BS can significantly improve both anatomical outcomes and quality of life in patients with HS
Gallagher et al. [17]	2017	2 patients with HS	BS may serve as an effective treatment for HS
Thomas et al. [18]	2014	1 patient with HS	BS may be an effective therapeutic option for HS
Kromann et al. [19]	2014	383 patients with HS	Weight loss resulting from BS was associated with a significant reduction in the number of patients experiencing HS symptoms
Marzano et al. [20]	2012	1 patient with HS	PASH syndrome may develop following BS
Garcovich et al. [21]	2016	1 patient with HS	BPD/DS can result in multiple cutaneous follicular hyperkeratotic inflammatory lesions and painful subcutaneous abscesses with draining sinuses and extensive fistulization
Garcovich et al. [22]	2019	178 patients with HS	Patients with HS who underwent BS were more likely to exhibit micronutrient deficiencies, particularly zinc
Psoriasis
Hossler et al. [23]	2013	34 patients with psoriasis	BS can improve, worsen, or have no effect on psoriatic symptoms in different patients
Odorici et al. [24]	2017	1 female patient with psoriasis	BS led to a marked improvement in psoriatic skin lesions
Romero-Talamas et al. [25]	2014	33 patients with obesity and psoriasis	RYGB may lead to a significant improvement in psoriasis symptoms in approximately 40% of patients
Farias et al. [26]	2012	12 patients dealing with psoriasis	BS has a significant positive effect on psoriatic skin lesions
Khaitan et al. [27]	2018	23 patients suffering from psoriasis	Psoriasis improved in nearly all patients following weight loss induced by BS
Egeberg et al. [28]	2016	12,364 patients who underwent GBP 1071 patients who underwent GB	GBP was more effective than GB in improving both psoriasis and psoriatic arthritis
Maglio et al. [29]	2017	1991 patients from the surgery group 2018 patients from the control group	BS was associated with a reduced risk of developing psoriasis compared with conventional obesity management
De Menezes Ettinger et al. [30]	2006	1 patient suffering from psoriasis	Patient experienced complete remission of psoriatic lesions following RYGB
Higa-Sansone et al. [31]	2004	1 patient dealing with psoriasis	Weight loss following LRYGBP should be considered a therapeutic strategy for managing severe psoriasis in patients with morbid obesity
Hossler et al. [32]	2011	2 patients with psoriatic lesions	Weight loss following GBP may serve as a useful adjunctive therapy for patients with obesity and psoriasis
Polycystic ovary syndrome
Lacey et al. [33]	2023	77 women with PCOS	BS can be effective in reducing hirsutism, improving subfertility and oligomenorrhea, and enhancing QoL in women with PCOS
Eid et al. [34]	2014	14 women with PCOS	Improvement in hirsutism was not directly associated with magnitude of weight loss
Singh et al. [35]	2020	50 women who underwent BS  18 women with PCOS (among 50) who underwent BS	BS results in improvements in clinical, hormonal, and radiological parameters associated with PCOS
Escobar-Morreale et al. [36]	2005	36 patients who were submitted to BS 18 patients with PCOS	PCOS may resolve following weight loss induced by BS
Różańska-Walędziak et al. [37]	2020	515 premenopausal women	No improvement in clinical symptoms of hyperandrogenism was observed in women with PCOS following BS
Legro et al. [38]	2012	29 reproductive-aged women with obesity	No significant change in hirsutism or acne scores was observed following weight loss induced by BS
Jamal et al. [39]	2011	566 women with obesity who underwent RYGB 31 women suffering from PCOS	Surgical weight loss following RYGB results in marked improvement of PCOS manifestations
Skin tags
Fang et al. [40]	2020	100 patients with obesity	In patients attending bariatric clinics, presence of skin tags was associated with higher SBP, HbA1c, and an increased prevalence of T2DM and HTN
Intertrigo
Kutluer et al. [41]	2021	60 female patients with obesity	Intertrigo was observed in 23% (14/60) of women with obesity undergoing BS
Boza et al. [8]	2011	76 patients with obesity 73 female patients with normal weight	Progression of intertrigo is associated with the rate of BMR following BS
Keratosis pilaris and pebble fingers
Itthipanichpong et al. [13]	2020	70 patients post-BS  46 patients with successful weight loss  24 patients with unsuccessful weight loss	Patients achieving successful weight loss following BS were less likely to present with KP and pebble fingers
Development of postoperative skin diseases
Ramos-Levi et al. [42]	2013	48-year-old woman with obesity	RYGB was associated with development of xeroderma in a patient who exhibited significantly reduced vitamin A levels postoperatively
Crestani et al. [43]	2020	39-year-old female patient	RYGB may increase the risk of itraconazole malabsorption during treatment of lymphocutaneous sporotrichosis
Yeager et al. [44]	2019	38-year-old African-American woman	GBP surgery may be associated with development of prurigo pigmentosa
Derderian et al. [45]	2020	217 study participants 198 patients with an abdominal pannus 16 patients with pannus-related symptoms	Abdominal pannus and pannus-related symptoms may represent complications following BS
Bae-Harboe et al. [46]	2012	An adult with obesity who underwent BS	Acquired zinc deficiency may develop following bariatric surgery and result in onset of AE
Cuhna et al. [47]	2012	Female patient with obesity	Both JIB and VG may lead to AE due to zinc deficiency
Ocon et al. [48]	2012	Patient who underwent BS	Development of phrynoderma, a follicular hyperkeratotic skin condition, following BS is associated with vitamin A deficiency
Stolle et al. [49]	2012	36-year-old female patient	GBP may predispose patients to the development of scurvy due to vitamin C deficiency
Rojas et al. [50]	2011	42 patients with mild hair loss 45 patients with severe hair loss	BS may lead to hair loss secondary to zinc deficiency
Ruiz-Tovar et al. [51]	2014	42 patients who underwent LSG	Hair loss is a common complication following LSG and is associated with rapid weight loss as well as reductions in zinc and iron levels
Moreira et al. [52]	2010	37 patients with obesity	BS may result in alopecia
Nadler et al. [53]	2007	53 teenagers with obesity	LAGB may represent a risk factor for hair loss
Neve et al. [54]	1996	130 patients who underwent VGP	VGP may cause hair loss
Triwatcharikorn et al. [55]	2023	31 patients	VGP may lead to hair loss
Tu et al. [56]	2011	A female patient	BS may be associated with development of BADAS
Light et al. [57]	2010	10 patients	Skin damage following BS may persist long-term, even after substantial weight loss
Robinson et al. [58]	2011	1 patient with obesity who underwent GBP	GBP may be a potential risk factor for development of metastatic angiosarcoma, as observed 4 years post-surgery
Ashourian et al. [59]	2006	1 patient with obesity who underwent RYGB	RYGB can lead to pellagra as a result of niacin deficiency
Cone et al. [60]	2004	A female patient who underwent BS	BS may predispose patients to development of purpura fulminans and DIC
Kovalevski et al. [61]	1997	39-year-old woman	BS may be associated with development of dermatitis herpetiformis
Danese et al. [62]	2011	53-year-old woman	BS may contribute to development of nonthrombocytopenic palpable purpura
Gamble et al. [63]	1982	A patient with obesity who underwent GBP	JIB may represent a risk factor for development of dermal vasculitis
Goldman et al. [64]	1979	2 patients with obesity who underwent GBP	JIB can predispose patients to development of dermal vasculitis
Williams et al. [65]	1979	A 32-year-old woman who underwent GBP	Nodular nonsuppurative panniculitis may develop following JIB surgery

Abbreviations: AE acrodermatitis enteropathica, AN acanthosis nigricans, BADAS bowel-associated dermatitis–arthritis syndrome, BMR body mass reduction, BPD/DS biliopancreatic diversion with duodenal switch, DIC disseminated intravascular coagulation, GB gastric banding, GBP gastric bypass, HbA1c elevated hemoglobin A1c, HS hidradenitis suppurativa, HTN hypertension, JIB jejunal-ileal bypass, LAGB laparoscopic adjustable gastric banding, LRYGBP laparoscopic Roux-en-Y gastric bypass, LSG laparoscopic sleeve gastrectomy, NC nutritional care, NLD necrobiosis lipoidica diabeticorum, PASH pyoderma gangrenosum, acne, and hidradenitis suppurativa, PCOS polycystic ovary syndrome, QoL quality of life, RYGB Roux-en-Y gastric bypass, SBP systolic blood pressure, T2DM type 2, VGP vertical gastroplasty

Acanthosis Nigricans

Acanthosis nigricans (AN) is a cutaneous disorder characterized by hyperpigmented, velvety plaques that most commonly affect intertriginous areas such as the neck, axillae, and groin. AN is strongly associated with insulin resistance and is frequently observed in patients with obesity, T2DM, and endocrine disorders. Additional etiologic factors include certain medications (e.g., systemic corticosteroids, nicotinic acid), genetic syndromes, and, rarely, paraneoplastic disease [9].

Fu et al. [10] demonstrated that laparoscopic sleeve gastrectomy (LSG) significantly improves obesity-related acanthosis nigricans (OB-AN). In their study, 86.5% of patients with OB-AN achieved complete or partial remission of skin lesions following LSG. Furthermore, improvement in AN was positively correlated with postoperative reductions in testosterone levels and with changes in skin pigmentation scores, suggesting a link between metabolic and hormonal improvements and cutaneous outcomes [10].

Zhu et al. [11] reported that LSG in men with obesity and AN resulted in both improvement of skin lesions and an increase in total testosterone levels. Given the anti-inflammatory effects of testosterone, the authors suggested that elevated postoperative testosterone may contribute to the observed amelioration of AN [11].

Zhang et al. [12] demonstrated that LSG positively affected both skin lesions and body composition in Chinese patients with obesity and AN. The study found that reductions in android fat mass and visceral adipose tissue were associated with improvements in insulin resistance, which likely contributed to the observed amelioration of AN [12].

Itthipanichpong et al. [13] further demonstrated that bariatric surgery is associated with a reduction in the prevalence of AN across the neck, axillae, and inguinal regions [13].

Confluent and Reticulated Papillomatosis

Confluent and reticulated papillomatosis (CARP) is a rare cutaneous disorder characterized by hyperpigmented, reticulated plaques, often affecting the trunk and upper back. Clinically, CARP may be mistaken for AN as a result of overlapping appearance in intertriginous areas. Evidence suggests that CARP can improve following weight loss. In one reported case, bariatric surgery led to complete resolution of the rash: initial improvement was noted after a 10-pound weight reduction, and full clearance occurred within 3 months postoperatively [14].

Necrobiosis Lipoidica

Necrobiosis lipoidica diabeticorum (NLD) is a rare, chronic cutaneous disorder characterized by shiny, yellowish-to-reddish-tan plaques with violaceous borders and visible underlying blood vessels. Although strongly associated with diabetes mellitus, NLD is believed to result from autoimmune-mediated vascular inflammation, leading to collagen degeneration and granuloma formation within the dermis and subcutaneous tissue. Lesions predominantly affect the lower extremities but may also occur on the arms, trunk, or face [15].

Bozkurt et al. [15] reported a case of NLD in which skin lesions resolved following bariatric surgery. Histopathological analysis prior to surgery revealed necrosis, collagen degeneration, and fibrosis. In this patient, conventional therapies—including topical corticosteroids, psoralen plus ultraviolet A (PUVA) therapy, and supportive dressings—were ineffective. Although the precise pathogenesis of NLD remains unclear, proposed contributing factors include microangiopathy, immune complex-mediated vasculitis, T cell-driven inflammation, proinflammatory cytokine activity, and abnormal collagen production [15].

Hidradenitis Suppurativa

Canard et al. [16] reported that bariatric surgery significantly improved both anatomical outcomes and quality of life in patients with hidradenitis suppurativa (HS). Postoperative reductions in lesion burden were accompanied by improvements in Dermatology Life Quality Index (DLQI) scores, indicating that weight loss plays a central role in ameliorating HS symptoms and enhancing metabolic health. Mechanistically, weight reduction is associated with decreased circulating proinflammatory cytokines, including tumor necrosis factor-α (TNFα) and various interleukins, which are implicated in HS pathogenesis [16].

Gallagher et al. [17] further suggested that bariatric surgery may serve as an effective treatment for HS, even in patients who have failed conventional therapies such as antibiotics or biologics. They reported a high prevalence of insulin resistance (approximately 55%) among patients with HS, highlighting a potential link between metabolic dysfunction and disease pathogenesis. In a case report, bariatric surgery markedly improved insulin resistance in patients with HS, which the authors attributed to reductions in circulating insulin levels [17].

Thomas et al. [18] provided further evidence supporting bariatric surgery as an effective intervention for HS, including in patients who have failed conventional therapies such as topical chlorhexidine and prolonged courses of oral antibiotics. The report described a 52-year-old patient with treatment-refractory HS who underwent laparoscopic sleeve gastrectomy. Following surgery, the patient experienced rapid improvement in HS lesions, accompanied by a reduction in BMI from 52 to 36 kg/m² within 3 months [18].

Kromann et al. [19] reported that weight loss exceeding 15% following bariatric surgery was associated with a 35% reduction in the proportion of patients experiencing HS symptoms, as well as a decrease in the mean number of affected skin areas from 1.93 to 1.22. These findings indicate that substantial weight reduction can significantly improve HS severity and overall symptom burden [19].

PASH syndrome is a rare autoinflammatory disorder characterized by the triad of pyoderma gangrenosum (PG), acne, and HS. Although the precise etiology remains unclear, it is believed to result from dysregulation of the innate immune system, leading to excessive inflammatory responses. Interestingly, the condition has been reported following bariatric surgery, suggesting that surgical intervention and associated metabolic changes may act as potential triggers for the syndrome [20].

Garcovich et al. [21] reported a case of a 47-year-old patient who developed multiple cutaneous lesions, including follicular hyperkeratotic inflammatory lesions, painful subcutaneous abscesses with draining sinuses, and extensive fistulization, following biliopancreatic diversion with duodenal switch (BPD/DS). BPD/DS significantly reduces nutrient and calorie absorption, which may result in nutritional deficiencies, alterations in the gut microbiome, and immune system dysregulation. Although the precise mechanism linking these changes to the development of skin lesions remains unclear, the extensive rerouting of the digestive tract and resultant malabsorption of fats and other nutrients may disrupt extracellular matrix homeostasis and other cellular processes in the skin [21].

Garcovich et al. [22] reported that patients undergoing bariatric surgery may have an increased risk of developing HS as a result of multiple contributing factors. Micronutrient deficiencies—including zinc, iron, vitamin D, and vitamin A—can impair immune function and promote follicular hyperkeratosis. Additional mechanisms involve gut microbiome alterations leading to systemic inflammation, changes in adipokine levels such as leptin and adiponectin, and modifications of the extracellular matrix within hair follicles, which may result in follicular occlusion [22].

Psoriasis

Hossler et al. [23] reported that bariatric surgery led to improvement in psoriasis in a subset of patients, with 22 individuals demonstrating clinical improvement, while 13 showed no change or experienced worsening symptoms. The authors proposed that weight reduction and associated decreases in pro-inflammatory mediators, including TNFα, may underlie these improvements. Notably, younger patients with a family history of psoriasis appeared to derive less benefit from bariatric surgery [23].

Odorici et al. [24] described a case in which a patient with psoriasis experienced marked clinical improvement following bariatric surgery, corresponding with a 30-kg weight reduction. The authors attributed this improvement to decreased adipose tissue, which may enhance the pharmacokinetics of biologic therapies such as infliximab by reducing fat-mediated drug sequestration, thereby improving systemic drug distribution and efficacy [24].

Romero-Talamas et al. [25] reported that RYGB resulted in significant improvement of psoriasis symptoms in approximately 40% of patients. Furthermore, the degree of clinical improvement was positively correlated with the magnitude of weight loss, highlighting a dose-dependent relationship between weight reduction and psoriasis outcomes [25].

Farias et al. [26] reported that bariatric surgery led to marked improvement of psoriasis in patients with obesity. Six months postoperatively, seven patients were free of skin lesions, and three of four patients receiving systemic therapy were able to discontinue treatment. Improvements in quality of life were also observed, with the mean DLQI decreasing significantly from 14.9 to 5. The authors attributed these outcomes to weight loss, reduction of systemic inflammation, and enhanced insulin sensitivity [26].

Khaitan et al. [27] reported that patients with psoriasis undergoing bariatric surgery experienced significant improvement in skin symptoms, accompanied by substantial reductions in weight and BMI. Notably, 55.6% of patients were able to discontinue systemic medications within 3 months postoperatively, with this proportion increasing to 94.4% at 1 year, indicating a sustained and clinically meaningful reduction in the need for immunosuppressive therapy [27].

Gastric bypass (GBP) has been shown to be more effective than gastric banding (GB) in improving psoriasis and psoriatic arthritis. This superior efficacy may be attributed to greater postoperative weight loss and alterations in nutrient absorption, which can reduce systemic inflammation and enhance insulin sensitivity. Additionally, GBP increases circulating levels of the gut hormone GLP-1, which promotes insulin secretion, suppresses glucagon release, and induces satiety via central GLP-1 receptor activation. GLP-1 also exhibits anti-inflammatory properties, including downregulation of TNFα and the nuclear factor kappa B (NF-κB) pathway, both of which are key mediators in psoriasis pathogenesis [28].

Maglio et al. [29] reported that bariatric surgery is associated with a reduced risk of developing psoriasis compared with standard obesity management. However, when formally comparing surgical techniques, no significant differences in risk reduction were observed among gastric bypass, vertical gastroplasty, and gastric banding procedures [29].

De Menezes Ettinger et al. [30] described a 56-year-old man with obesity (BMI 46.9 kg/m²), HTN, and gastroesophageal reflux disease (GERD) who experienced complete remission of severe psoriasis persisting for 39 years following RYGB. Four months postoperatively, the patient lost 23 kg, and psoriatic lesions on the face, hands, elbows, knees, and buttocks resolved entirely without additional pharmacologic therapy [30].

Higa-Sansone et al. [31] reported a case of a 55-year-old man with a 15-year history of severe psoriasis who achieved complete resolution of skin symptoms following laparoscopic Roux-en-Y gastric bypass (LRYGB). The patient lost 39 kg postoperatively, and psoriatic lesions fully resolved within 12 months. Notably, the remission was sustained, with no recurrence observed during the subsequent 2 years [31].

Hossler et al. [32] reported that two patients with obesity and psoriasis experienced significant improvement of skin lesions following GBP, suggesting that weight reduction may serve as an effective adjunctive therapy. The authors hypothesized that weight loss mitigates chronic inflammation associated with obesity, including elevated T helper 1 (Th1) lymphocytes and TNFα. These findings support previous evidence linking obesity-driven systemic inflammation with psoriasis severity, indicating that bariatric surgery-induced weight loss may contribute to improved clinical outcomes in patients with psoriasis [32].

Hirsutism

Lacey et al. [33] reported that bariatric surgery significantly reduced the prevalence of hirsutism in women with PCOS, from 64% preoperatively to 19% postoperatively. In addition, patients experienced improvements in quality of life, highlighting the multifaceted benefits of weight reduction in this population [33].

Eid et al. [34] reported that bariatric surgery led to a reduction in hirsutism in 4 of 14 women with PCOS at 12 months postoperatively, decreasing the number of affected patients from 11 to 7. The authors suggested that this improvement was not solely dependent on the magnitude of weight loss, but rather on the correction of underlying metabolic abnormalities, including dysregulated testosterone, glucose, insulin, and lipid levels in women with obesity and PCOS [34].

Singh et al. [35] reported that 44% of women (5/11) experienced complete resolution of hirsutism 1 year after bariatric surgery, with the median Ferriman–Gallwey (FG) score decreasing from 11 to 9. A positive correlation was observed between weight loss at 6 months and reductions in serum testosterone levels at 1 year (p < 0.05). Bariatric surgery reduces insulin resistance, adipokine concentrations, and systemic inflammatory mediators, including interleukin-6 (IL-6) and TNFα. These metabolic and inflammatory changes contribute to decreased luteinizing hormone-mediated androgen secretion by the pituitary and reduced peripheral aromatization of androgens to estrogens, ultimately improving hyperandrogenic symptoms such as hirsutism [35].

Escobar-Morreale et al. [36] reported that weight loss induced by bariatric surgery is associated with reductions in fasting glucose, total and free testosterone, androstenedione, and dehydroepiandrosterone sulfate (DHEA-S) levels, highlighting the surgery’s beneficial effects on metabolic and hyperandrogenic parameters in women with obesity [36].

In contrast, Różańska-Walędziak et al. [37] reported that bariatric surgery did not result in significant improvement of clinical hyperandrogenism—including hirsutism and acne—in women with PCOS, highlighting that surgical weight loss may not uniformly affect all hyperandrogenic symptoms [37].

Similarly to the study by Różańska-Walędziak et al. [37], Legro et al. [38] found no significant change in hirsutism or acne scores after weight loss following bariatric surgery [38].

Jamal et al. [39] reported that hirsutism completely resolved in 29% (4/14) of patients and partially improved in 9% (1/14) following bariatric surgery. Improvements were self-assessed by patients, characterized as either complete resolution or a reduction in hair thickness and density. Notably, the degree of hirsutism improvement was positively correlated with the extent of weight loss, with patients losing 45% or more of their body weight being more likely to achieve complete resolution [39].

Skin Tags

Fang et al. [40] reported that the presence of skin tags in patients who were obese and undergoing bariatric surgery was associated with higher systolic blood pressure, elevated hemoglobin A1c (HbA1c), and an increased prevalence of T2DM and HTN. Interestingly, lipid profiles did not differ significantly between patients with and without skin tags [40].

Intertrigo

Intertrigo is an inflammatory condition affecting intertriginous areas such as the underarms, groin, and buttocks. Kutluer et al. [41] reported that intertrigo affected 23% of the women with obesity studied, making it the second most prevalent skin condition after striae. The condition arises from a combination of heat, moisture, and friction, all of which are exacerbated by obesity as a result of increased sweating and mechanical irritation. Furthermore, obesity-related comorbidities, such as diabetes, can elevate the risk of secondary skin infections in affected areas [41].

Boza et al. [8] reported that the severity of intertrigo is influenced by the rate of body mass reduction following bariatric surgery. The authors noted that skin laxity, a common consequence of rapid weight loss, can complicate the management of intertrigo. They suggested that definitive treatment should ideally be delayed until significant weight loss and skin tightening have occurred, with body contouring procedures potentially serving as an optimal approach for removing excess skin and preventing recurrent intertrigo [8].

Keratosis Pilaris and Pebble Fingers

Keratosis pilaris (KP) is a common skin disorder characterized by small, rough follicular papules, often on the arms and thighs. Pebble fingers, a related manifestation, are linked to insulin resistance (IR). Itthipanichpong et al. [13] reported that patients who achieved successful weight loss following bariatric surgery were less likely to present with KP and pebble fingers compared with those who experienced less weight reduction. The authors hypothesized that improvements in insulin resistance following weight loss may underlie the observed decrease in these skin manifestations [13].

Skin Diseases That Developed After Bariatric Surgery

Ramos-Levi et al. [42] reported a case of xeroderma developing after RYGB. Xeroderma is characterized by dry, scaly skin and can result from vitamin A deficiency, as well as from underlying dermatologic conditions such as eczema or psoriasis. In this patient, serum vitamin A levels were markedly reduced following RYGB, and clinical examination revealed eczematous and erythematous desquamative plaques consistent with xeroderma. The authors concluded that the condition arose from a combination of vitamin A deficiency and pre-existing eczema. Treatment with vitamin A supplementation and topical corticosteroids led to complete resolution. This case underscores the importance of monitoring nutritional status after bariatric surgery, as patients are at risk of developing deficiencies, including vitamin A [42].

Crestani et al. [43] reported a case of lymphocutaneous sporotrichosis developing after RYGB. The patient was unresponsive to itraconazole, which is poorly absorbed following RYGB as a result of altered gastric pH and reduced small intestinal surface area. Treatment with terbinafine, a lipophilic antifungal absorbed passively in the intestine, was successful, highlighting its utility as an alternative therapy in patients with altered gastrointestinal anatomy after bariatric surgery [43].

Yeager et al. [44] reported a case of prurigo pigmentosa (PP) developing after gastric bypass surgery. PP is characterized by pruritic, erythematous papules and papulovesicles, typically affecting the trunk and neck. In this patient, the rash appeared 2 weeks postoperatively, initially presenting as pruritic palms and small papules on the lower back, later spreading to patchy areas of the lower back, chest, lateral neck, and postauricular regions. Treatment with minocycline 100 mg twice daily for 2 weeks resulted in resolution of the rash, although residual hyperpigmentation persisted [44].

Derderian et al. [45] reported that of 217 patients undergoing bariatric surgery, 198 (90%) had an abdominal pannus and 16 (7%) experienced pannus-related symptoms at the time of surgery. Higher preoperative BMI was significantly associated with greater postoperative pannus severity, an association that remained significant after adjusting for waist circumference, sagittal abdominal diameter, and gender (p = 0.0003). Specifically, each 5 kg/m² increase in preoperative BMI increased the odds of higher pannus severity by 1.8-fold. The analysis also accounted for BMI, time after surgery, gender, and surgical type, all of which were linked to postoperative pannus symptoms (p < 0.002). Interestingly, patients with a higher preoperative pannus grade experienced greater reductions in pannus severity postoperatively (p < 0.0001) but also had a higher incidence of pannus-related symptoms after surgery (p = 0.002) [45].

Bae-Harboe et al. [46] described a case of acquired acrodermatitis enteropathica (AE) in an adult following bariatric surgery. AE is a rare dermatologic disorder resulting from zinc deficiency. While the inherited form is due to genetic mutations, the acquired form develops secondary to conditions such as postoperative malabsorption. Clinically, both forms share similar features, including characteristic periorificial and acral skin lesions, alopecia, and diarrhea [46].

Cuhna et al. [47] reported a case of acquired AE in a female patient following jejunoileal bypass (JIB) and vertical gastroplasty (VGP). Both procedures can induce significant weight loss but increase the risk of nutrient deficiencies, including protein and zinc. The patient lost 58 kg postoperatively and was diagnosed with AE 7 months later, with laboratory testing confirming low plasma zinc levels. Skin lesions resolved within 1 week of zinc supplementation at 1000 mg/day [47].

Ocon et al. [48] reported a case linking vitamin A deficiency to phrynoderma, a condition characterized by follicular hyperkeratosis, following bariatric surgery. The patient presented with phrynoderma, night blindness, and xerophthalmia, all consistent with vitamin A deficiency, and laboratory testing confirmed low serum vitamin A levels. High-dose vitamin A supplementation led to clinical improvement, highlighting the importance of monitoring vitamin A status in patients after bariatric surgery [48].

Stolle et al. [49] reported a case of scurvy developing after gastric bypass surgery, attributed to factors such as inadequate dietary intake and smoking. The condition was successfully managed with vitamin C supplementation, resulting in rapid symptom improvement [49].

Rojas et al. [50] suggested that higher dietary intake of zinc and iron, along with minimized postoperative deficiencies in these minerals, may help reduce hair loss following bariatric surgery. These findings indicate that maintaining adequate zinc and iron levels is important for supporting hair growth and preventing postoperative alopecia [50].

Ruiz-Tovar et al. [51] reported that hair loss is a common complication following LSG, primarily associated with rapid weight loss and deficiencies in zinc and iron. These findings are consistent with other studies indicating that postoperative alopecia frequently occurs after bariatric procedures such as RYGB and LSG, with micronutrient deficiencies, particularly zinc and iron, playing a central role [51].

Moreira et al. [52] reported that alopecia is a frequent complication following bariatric surgery, affecting 10 of 28 patients (36%) at both 30 and 90 days postoperatively [52].

Nadler et al. [53] reported that 5 of 53 adolescents who underwent laparoscopic adjustable gastric banding (LAGB) experienced postoperative hair loss. However, the study was limited by its small sample size, and the timing of hair loss onset was not specified. Further research is needed to establish the true incidence and temporal pattern of alopecia in adolescent patients following LAGB [53].

Neve et al. [54] reported that zinc sulfate supplementation may effectively treat postoperative hair loss following vertical gastroplasty (VG). In their study, 47 of 130 patients developed alopecia despite taking a standard multivitamin supplement. These patients were subsequently treated with zinc sulfate at a dose of 200 mg three times daily, resulting in cessation of hair loss and promotion of hair regrowth in all cases [54].

Triwatcharikorn et al. [55] reported that acute telogen effluvium (TE) occurred in 17 of 31 patients (54.8%) following bariatric surgery. TE is a form of hair loss characterized by a sudden increase in the proportion of hairs entering the telogen (resting) phase of the hair growth cycle. This condition can be triggered by factors such as physiological stress, illness, and rapid weight loss [55].

Tu et al. [56] reported a case of bowel-associated dermatosis–arthritis syndrome (BADAS) developing 12 months after bariatric surgery. The patient presented with ulcerative and pustular skin lesions, polyarticular arthritis with joint effusions, and fever. Skin biopsy revealed a superficial to mid-dermal neutrophilic dermatosis, confirming the diagnosis. Initial treatment with corticosteroids and antibiotics was insufficient, and disease control was achieved only after initiation of colchicine. This case underscores the importance of considering BADAS in the differential diagnosis of patients presenting with skin lesions, arthritis, and fever following bariatric surgery [56].

Light et al. [57] reported that patients undergoing bariatric surgery may experience long-lasting alterations in the skin’s extracellular matrix, even after substantial weight loss. Histological analysis revealed poorly organized collagen, elastin degradation, and scar formation, which can persist in visually normal skin. These findings highlight that bariatric surgery-related changes in skin structure may contribute to lasting dermatologic sequelae [57].

Robinson et al. [58] reported a rare case of metastatic angiosarcoma in a patient 4 years after gastric bypass surgery, complicated by chronic lymphedema. This case highlights the malignant potential and diverse origins of angiosarcoma, a vascular tumor, and suggests a possible association with chronic lymphedema [58].

Ashourian et al. [59] reported a case of pellagra developing 3 months after RYGB. Pellagra, caused by niacin deficiency, presents with a classic triad of dermatitis, diarrhea, and dementia. The patient exhibited dermatitis characterized by erythema, hyperpigmentation, and scaling in sun-exposed areas (neck, face, and hands), along with glossitis and angular cheilitis. RYGB can predispose patients to micronutrient deficiencies, including niacin, as a result of bypass of the stomach and small intestinal regions responsible for absorption. Rapid postoperative weight loss, in this case 45 kg over 4 months, may have further contributed to the development of niacin deficiency [59].

Cone et al. [60] reported a case of purpura fulminans complicated by disseminated intravascular coagulation (DIC) following bariatric surgery. The authors suggested that malabsorption of vitamin K-dependent proteins, including protein C, protein S, and antithrombin, predisposed the patient to these severe coagulopathic complications [60].

Kovalevski et al. [61] reported a case of a pruritic eruption in a patient following bariatric surgery and initiation of a liquid protein diet. The eruption, initially diagnosed as PP, presented with multiple excoriations and erythematous plaques and patches with central clearing on the trunk and extremities. Initial treatment with 0.05% fluocinonide cream was ineffective. Skin biopsy revealed subepidermal clefts in the dermal papillae filled with neutrophils, microvesiculation, and a perivascular mononuclear infiltrate with neutrophils. Direct immunofluorescence showed granular IgA deposits in the dermal papillae, and endomysial IgA antibodies were positive at a titer of 5, consistent with dermatitis herpetiformis, a gluten-sensitive enteropathy. The patient’s rash resolved within 3 months after discontinuing the liquid protein diet and initiating a gluten-free diet. This case underscores the importance of considering gluten-sensitive enteropathy in patients who develop pruritic rashes following bariatric surgery, particularly when exposed to high-gluten diets [61].

A 53-year-old woman with morbid obesity (BMI 41.6 kg/m²) was diagnosed with Henoch–Schönlein purpura (HSP), presenting with purpuric lesions on the lower legs and diarrhea. Skin biopsy demonstrated leukocytoclastic vasculitis. Initial treatment with immunosuppressants led to temporary remission, but the rash later relapsed. The patient subsequently underwent biliopancreatic diversion, resulting in a substantial BMI reduction to 25 kg/m². This case suggests that bariatric surgery may influence autoimmune phenomena, potentially through the formation of immune complexes secondary to excess intestinal bacterial antigens [62].

Gamble et al. [63] reported a case of glomerulonephritis and dermal vasculitis occurring 4 years after a JIB for morbid obesity. JIB, which involves bypassing a portion of the small intestine, can result in nutrient and antibody malabsorption. In this patient, impaired antibody absorption likely contributed to the development of glomerulonephritis and cutaneous vasculitis, reducing the immune system’s ability to respond effectively to infection [63].

Goldman et al. [64] reported a case of glomerulonephritis and dermal vasculitis occurring 4 years after a JIB for morbid obesity. Skin biopsy confirmed chronic focal leukocytoclastic vasculitis. JIB, which shortens the functional length of the small intestine, can result in nutrient and antibody malabsorption. In this patient, impaired antibody absorption likely contributed to the formation of immune complexes, which deposited in tissues including the kidneys and blood vessels, causing inflammation and tissue damage [64].

Williams et al. [65] reported a case of nodular nonsuppurative panniculitis developing after JIB surgery. The patient presented with tender, erythematous nodules on the legs, thighs, and abdomen. Although this association requires further investigation, the case highlights JIB as a potential risk factor for this rare inflammatory skin condition and underscores the importance of monitoring for postoperative dermatologic complications [65].

Limitations

A key limitation of this review is the heterogeneity of the included studies and patient populations. Variations in study design, sample size, baseline characteristics, and quality of the reported data may influence outcomes and limit the generalizability of the findings. Consequently, differences between patient groups could affect the observed effects of bariatric surgery on skin conditions, making it challenging to draw definitive conclusions.

Conclusions

Bariatric surgery exerts a complex and sometimes contradictory influence on skin conditions. It can lead to the resolution of several dermatologic issues, including acanthosis nigricans, confluent and reticulated papillomatosis, necrobiosis lipoidica, hidradenitis suppurativa, psoriasis, hirsutism, skin tags, intertrigo, keratosis pilaris, and pebble fingers. Conversely, bariatric surgery may exacerbate or induce other conditions, such as xeroderma, sporotrichosis, prurigo pigmentosa, bowel-associated dermatosis–arthritis syndrome, pellagra, disseminated intravascular coagulation, purpura, vasculitis, panniculitis, and alopecia. These findings highlight the need for careful dermatologic monitoring before and after surgery. Further research is warranted to elucidate the underlying mechanisms and to optimize strategies for preventing and managing skin complications in patients undergoing bariatric surgery.

Author Contributions

Conceptualization, Mateusz Matwiejuk and Hanna Myśliwiec; methodology, Mateusz Matwiejuk and Hanna Myśliwiec; software, Mateusz Matwiejuk; validation, Mateusz Matwiejuk, Hanna Myśliwiec, Agnieszka Mikłosz, Adrian Chabowski, and Iwona Flisiak; formal analysis, Hanna Myśliwiec; investigation, Mateusz Matwiejuk; resources, Hanna Myśliwiec; data curation, Mateusz Matwiejuk; writing—original draft preparation, Mateusz Matwiejuk; writing—review and editing, Mateusz Matwiejuk, Hanna Myśliwiec, Agnieszka Mikłosz, Adrian Chabowski, and Iwona Flisiak; visualization, Mateusz Matwiejuk and Hanna Myśliwiec; supervision, Hanna Myśliwiec, Agnieszka Mikłosz, Adrian Chabowski and Iwona Flisiak; project administration, Hanna Myśliwiec; funding acquisition, Hanna Myśliwiec. All authors have read and agreed to the published version of the manuscript.

Funding

No funding or sponsorship was received for this study or the publication of this article. The Rapid Service Fee was funded by the Medical University of Bialystok.

Data Availability

Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study.

Declarations

Conflicts of Interest

The authors (Mateusz Matwiejuk, Hanna Myśliwiec, Agnieszka Mikłosz, Adrian Chabowski, Iwona Flisiak) declare no conflict of interest.

Ethical Approval

This article is based on previously conducted studies and does not contain any new studies with human participants or animals performed by any of the authors.