ABSTRACT
Hidradenitis suppurativa (HS) often leads to painful episodes requiring emergency department (ED) care, yet little is known about the comorbidities associated with these visits in pediatric patients. This study examined the Nationwide Emergency Department Sample (NEDS) from 2006 to 2019, identifying HS diagnoses via ICD‐9 and ICD‐10 codes to evaluate associated comorbidities. Pediatric HS ED visits were linked with 17 comorbidities, including systemic lupus erythematosus, as well as various psychosocial, endocrine, and dermatologic conditions. These findings highlight the need for expanded comorbidity screening in pediatric HS care.
Keywords: comorbidities, emergency department, hidradenitis suppurativa, HS, pediatric dermatology
1. Introduction
Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition caused by follicular occlusion, leading to painful nodules, sinus tracts, and scarring. HS is associated with metabolic syndrome, depression, inflammatory bowel disease, and inflammatory arthritis in adults, but pediatric studies are limited [1, 2]. This study aimed to identify comorbidities in pediatric patients with HS utilizing emergency department (ED) services.
2. Methods
This study was approved by Northwestern IRB STU00214408. Data were integrated from 2006 to 2019 Nationwide Emergency Department Sample (NEDS), providing an annual 20% stratified cross‐sectional sample of US hospital EDs. All data were de‐identified and limited to pediatric patients (< 18 years old). Diagnosis of HS was identified using ICD‐9705.83 and ICD‐10 L73.2 codes. Identification of HS and comorbidities is presented in Data S1. Statistical analysis was conducted using SAS 9.4. Descriptive statistics, including weighted means and confidence intervals, were calculated, and a chi‐square test was performed to determine the p value. Odds ratio was adjusted for age, gender, and insurance status via logistic regression model.
3. Results
Pediatric patients with HS in the ED had increased prevalence of anxiety and depression compared to patients without HS but showed decreased risk due to strong confounding effects. No significant association was observed for tobacco use, schizophrenia, opioid use, or homelessness. HS was associated with a higher prevalence of psoriasis (OR = 4.68), acne (OR = 10.44), pilonidal cyst (OR = 4.59), pyoderma gangrenosum (OR = 52.64) (all p < 0.0001), and atopic dermatitis (OR = 2.07; p = 0.04) (Table 1). HS was not statistically associated with vitiligo.
TABLE 1.
Frequency and odds ratios for comorbidities and social determinants of health of HS using ICD‐9 and ICD‐10 coding.
| Primary diagnosis of disease | Children with HS (weighted n = 31,362) | Children without HS (weighted n = 404,000,000) | Univariate model odds ratios [95% CI] | p | Multivariate model a odds ratios [95% CI] | p | ||
|---|---|---|---|---|---|---|---|---|
| Weighted frequency (95% CI) | Weighted % prevalence (95% CI) | Weighted frequency (95% CI) | Weighted % prevalence (95% CI) | |||||
| Conditions of skin and soft tissue | ||||||||
| Psoriasis | 49 | 0.1 (0.02–0.18) | 46,848 | 0.01 (0.0112–0.0120) | 8.66 [3.79–19.75] | < 0.0001 | 4.68 [2.05–10.67] | < 0.0001 |
| Acne | 365 | 0.75 (0.56–0.94) | 203,731 | 0.05 (0.0485–0.0522) | 15.09 [11.71–19.45] | < 0.0001 | 10.44 [8.07–13.51] | < 0.0001 |
| Pyoderma gangrenosum | 13 | 0.027 (0–0.06) | 882 | 0.0002 (0.0002–0.0003) | 124.94 [39.61–394.06] | < 0.0001 | 52.64 [16.30–168.93] | < 0.0001 |
| Pilonidal cyst | 417 | 0.86 (0.67–1.05) | 240,379 | 0.06 (0.0581–0.0608) | 14.54 [11.64–18.17] | < 0.0001 | 4.59 [3.67–5.75] | < 0.0001 |
| Vitiligo | 10 | 0.02 (0–0.05) | 19,694 | 0.0049 (0.0045–0.0053) | 4.19 [1.05–16.78] | 0.043 | 2.54 [0.64–10.15] | 0.19 |
| Atopic dermatitis | 52 | 0.11 (0.03–0.18) | 496,022 | 0.12 (0.11–0.13) | 0.87 [0.44–1.72] | 0.69 | 2.07 [1.04–4.10] | 0.04 |
| Psychosocial | ||||||||
| Depression | 850 | 1.75 (1.37–2.12) | 4,141,559 | 1.02 (0.99–1.06) | 1.74 [1.41–2.16] | < 0.0001 | 0.54 [0.44–0.67] | < 0.0001 |
| Anxiety | 640 | 1.32 (1.05–1.59) | 3,304,859 | 0.8396 (0.8121–0.8671) | 1.58 [1.29–1.94] | < 0.0001 | 0.51 [0.41–0.62] | < 0.0001 |
| Tobacco use | 1464 | 3.01 (2.60–3.42) | 4,153,895 | 1.03 (0.97–1.08) | 2.99 [2.64–3.39] | < 0.0001 | 0.89 [0.78–1.01] | 0.07 |
| Schizophrenia | 68 | 0.14 (0.07–0.21) | 316,233 | 0.08 (0.0751–0.0813) | 1.80 [1.09–2.97] | 0.02 | 0.67 [0.41–1.11] | 0.12 |
| Opioid use | 20 | 0.04 (0.0005–0.0820) | 120,889 | 0.03 (0.0283–0.0315) | 1.38 [0.52–3.70] | 0.52 | 0.47 [0.18–1.26] | 0.13 |
| Homelessness | 6 | 0.01 (0–0.04) | 34,788 | 0.0086 (0.0078–0.0094) | 1.40 [0.20–9.95] | 0.73 | 0.68 [0.10–4.81] | 0.7 |
| Endocrine | ||||||||
| Metabolic syndrome | 112 | 0.23 (0.13–0.34) | 19,073 | 0.0047 (0.0042–0.0052) | 49.23 [31.44–77.11] | < 0.0001 | 17.98 [11.47–28.18] | < 0.0001 |
| Diabetes mellitus type 1 | 416 | 0.85 (0.67–1.04) | 866,842 | 0.21 (0.20–0.22) | 4.01 [3.23–5.00] | < 0.0001 | 1.83 [1.47–2.28] | < 0.0001 |
| Diabetes mellitus type 2 | 1058 | 2.18 (1.80–2.55) | 842,336 | 0.21 (0.20–0.21) | 10.69 [8.98–12.74] | < 0.0001 | NA | NA |
| Obesity | 2661 | 5.47 (4.81–6.14) | 1,019,153 | 0.25 (0.24–0.26) | 22.97 [20.37–25.90] | < 0.0001 | 8.90 [7.92–10.00] | < 0.0001 |
| High cholesterol and lipid disorders | 180 | 0.37 (0.35–0.69) | 113,638 | 0.03 (0.0267–0.0295) | 13.25 [8.55–20.53] | < 0.0001 | 5.24 [3.39–8.10] | < 0.0001 |
| Polycystic ovary syndrome | 249 | 0.51 (0.33–0.69) | 59,000 | 0.015 (0.0139–0.0153) | 35.34 [25.03–49.90] | < 0.0001 | 8.21 [5.82–11.57] | < 0.0001 |
| Pulmonary | ||||||||
| Obstructive sleep apnea | 253 | 0.52 (0.35–0.69) | 221,242 | 0.05 (0.05–0.06) | 9.55 [6.96–13.11] | < 0.0001 | 9.33 [6.86–12.71] | < 0.0001 |
| Asthma | 3420 | 7.03 (6.33–7.73) | 27,082,437 | 6.7 (6.54–6.86) | 1.06 [0.96–1.16] | 0.28 | 0.96 [0.88–1.06] | 0.43 |
| Gastrointestinal | ||||||||
| Crohn's disease | 248 | 0.51 (0.39–0.71) | 161,646 | 0.04 (0.0375–0.0424) | 12.84 [8.69–18.98] | < 0.0001 | 5.04 [3.43–7.43] | < 0.0001 |
| Ulcerative colitis | 20 | 0.04 (0–0.08) | 61,273 | 0.02 (0.0140–0.0163) | 2.69 [0.96–7.51] | 0.06 | 1.06 [0.37–3.00] | 0.92 |
| Rheumatologic | ||||||||
| Systemic lupus erythematosus | 105 | 0.22 (0.07–0.36) | 81,983 | 0.02 (0.0375–0.0424) | 10.80 [5.58–20.90] | < 0.0001 | 2.95 [1.53–5.72] | 0.0013 |
| Rheumatoid arthritis | 67 | 0.14 (0.06–0.21) | 93,465 | 0.02 (0.0221–0.0242) | 6.00 [3.45–10.45] | < 0.0001 | 2.38 [1.37–4.16] | 0.0023 |
| Genetic | ||||||||
| Down syndrome | 550 | 1.13 (0.06–0.21) | 40,887 | 0.1 (0.10–0.11) | 11.35 [8.81–14.63] | < 0.0001 | 20.40 [15.74–26.28] | < 0.0001 |
Note: Bold indicates statistically significant p values.
Adjusted for age, gender, and insurance status.
Metabolic syndrome (OR = 17.98), diabetes mellitus type 1 (OR = 1.83), high cholesterol and lipid disorders (OR = 5.24), obesity (OR = 8.90), polycystic ovarian syndrome (PCOS) (OR = 8.21), and obstructive sleep apnea (OSA) (OR = 9.33) were strongly associated with HS (all p < 0.0001).
Systemic lupus erythematosus (SLE) (OR = 2.95; p = 0.0013) and rheumatoid arthritis (OR = 2.38; p = 0.0023) were more prevalent in pediatric patients with HS. Down syndrome was 20.40 times more prevalent within our study cohort (p < 0.0001). Crohn's disease was significantly associated with HS (OR = 5.04; p < 0.0001), while ulcerative colitis was not (Table 1).
4. Discussion
Depression and anxiety are common in patients with HS, with pediatric rates reported at 19% and 22% [3], respectively. Similarly, our study demonstrated higher levels of depression and anxiety in pediatric HS patients utilizing the ED. However, after adjustment for age, gender, and insurance status, the association showed ORs less than 1, which indicates risks for depression and anxiety were actually lower in subgroups of HS patients. Therefore, screening for psychosocial comorbidities needs to consider patients' demographic and socioeconomic status in HS care.
Consistent with prior pediatric HS studies [3, 4], we observed a higher prevalence of acne and pyoderma gangrenosum. The association between atopic dermatitis and HS remains unclear [5, 6]. We found that pediatric patients with HS have 2.07 times greater odds of atopic dermatitis compared to those without. Given that 60% of patients develop atopic dermatitis in the first year of life [7], it may be a key comorbidity in pediatric HS. Similar to prior studies [3, 4], we found significantly increased odds of pilonidal cyst in pediatric patients with HS. Notably, pilonidal cyst was analyzed as a distinct comorbidity.
Our study also highlights the high burden of metabolic comorbidities in pediatric patients with HS. Metabolic syndrome, obesity, dyslipidemia, and insulin resistance were all correlated with HS in the pediatric ER setting. Psoriasis, PCOS, and OSA, all associated with metabolic comorbidities, were also more prevalent in our cohort. These findings suggest metabolic dysregulation may drive HS development. Future studies should evaluate whether poor comorbidity control exacerbates HS.
Limited reports have demonstrated an association between SLE and HS in adults [8, 9]. Our study found SLE to be significantly associated with pediatric HS. Adalimumab, a TNF‐alpha inhibitor approved for patients 12 years and older in 2018, has a well‐known side effect of drug‐induced lupus. Given this potential adverse reaction and their inflammatory etiologies, further exploration of this relationship is essential to guide therapeutic interventions.
Our study is limited by its cross‐sectional design and by its sole focus on patients presenting to the ED, which introduces bias toward individuals with more severe disease. Additionally, pediatric HS may present subtly, which may contribute to underdiagnosis and underrepresentation in ICD‐coded data.
5. Conclusion
This study highlights the complex nature of pediatric HS in the ED setting. A holistic approach to comorbidity screening is essential for comprehensive management and improving outcomes in pediatric patients with HS.
Ethics Statement
This work was approved by Northwestern IRB; approval #STU00214408.
Conflicts of Interest
Dr. Riley has served as an advisory board member for Novartis Pharmaceuticals. Dr. Flood has received fellowship funding from AbbVie, Janssen, and the National Psoriasis Foundation, paid directly to her institution. The other authors declare no conflicts of interest.
Supporting information
Data S1: Supporting Information.
Hailemichael R., Martin S. A., Hwang A., Riley J. M., Flood K. S., and Ren Z., “Comorbidities of Pediatric Patients With Hidradenitis Suppurativa in the Emergency Department Setting: A Cross‐Sectional Study,” Pediatric Dermatology 43, no. 2 (2026): 365–368, 10.1111/pde.70054.
Funding: The authors received no specific funding for this work.
Data Availability Statement
The data that support the findings of this study are available from the corresponding author upon reasonable request.
References
- 1. Lambert R. A. and Stein S. L., “Pediatric Hidradenitis Suppurativa: Describing Care Patterns in the Emergency Department,” Pediatric Dermatology 40, no. 3 (2023): 434–439. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2. Choi E., Ooi X. T., and Chandran N. S., “Hidradenitis Suppurativa in Pediatric Patients,” Journal of the American Academy of Dermatology 86, no. 1 (2022): 140–147. [DOI] [PubMed] [Google Scholar]
- 3. Seivright J. R., Collier E., Grogan T., Hogeling M., Shi V. Y., and Hsiao J. L., “Physical and Psychosocial Comorbidities of Pediatric Hidradenitis Suppurativa: A Retrospective Analysis,” Pediatric Dermatology 38, no. 5 (2021): 1132–1136. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4. Garg A., Malviya N., Strunk A., et al., “Comorbidity Screening in Hidradenitis Suppurativa: Evidence‐Based Recommendations From the US and Canadian Hidradenitis Suppurativa Foundations,” Journal of the American Academy of Dermatology 86, no. 5 (2022): 1092–1101. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5. Kaakati R. N., Tanaka J., Liu B., et al., “Atopic Dermatitis Is Associated With Hidradenitis Suppurativa Diagnosis: A Single Institution Retrospective Cohort Study,” JAAD International 4 (2021): 18–24. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6. Sherman S., Kridin K., Bitan D. T., Leshem Y. A., Hodak E., and Cohen A. D., “Hidradenitis Suppurativa and Atopic Dermatitis: A 2‐Way Association,” Journal of the American Academy of Dermatology 85, no. 6 (2021): 1473–1479. [DOI] [PubMed] [Google Scholar]
- 7. Eichenfield L. F., Stripling S., Fung S., Cha A., O'Brien A., and Schachner L. A., “Recent Developments and Advances in Atopic Dermatitis: A Focus on Epidemiology, Pathophysiology, and Treatment in the Pediatric Setting,” Paediatric Drugs 24, no. 4 (2022): 293–305. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8. Ben David C., Bragazzi N. L., Watad A., et al., “Hidradenitis Suppurativa Associated With Systemic Lupus Erythematosus: A Case Report,” Medicine (Baltimore) 97, no. 12 (2018): e0186. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9. Kassels A., Park S., Hsiao J. L., and Kraus C. N., “Hidradenitis Suppurativa Is Associated With Inflammatory Arthritis, Systemic Lupus Erythematosus, and Other Autoimmune Diseases: A Retrospective Population‐Level Study,” JAAD International 17 (2024): 55–57. [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Data S1: Supporting Information.
Data Availability Statement
The data that support the findings of this study are available from the corresponding author upon reasonable request.