Beyond the Surface: Decoding Pityriasis Versicolor Through Clinical, Dermoscopic and Microbiological Exploration

Abstract

Background:

Pityriasis versicolor (PV) is an asymptomatic, superficial fungal infection caused by the Malassezia species and causes discolouration of the skin leading to altered pigmentation. It is usually a clinical diagnosis, but in doubtful cases wherein potassium hydroxide (KOH) mount is unavailable, alternative modalities like dermoscopy aid in the management.

Aims and Objectives:

To evaluate the clinical and dermoscopic patterns in PV and correlate with the associated risk factors and study the fungal culture.

Materials and Methods:

A cross-sectional observational study was conducted for 12 months. A total of 115 patients clinically diagnosed with PV showing positivity on KOH mount were recruited. Dermoscopy was done, following which the scales were scraped and cultured in the laboratory on Saborauds dextrose agar and modified Dixon media, and the results were analysed after 3 weeks.

Results:

Among the 115 participants, on clinical evaluation, 79 patients had achromic and 36 patients had chromic lesions. The dermoscopic features were categorized into domains such as scaling, pigmentation and other features. Fine scaling was the most common feature observed in 88.7% of the patients. Pigmentary changes were noted in all the patients with non-uniform pigmentation being the most common. We have also observed and described newer dermoscopic findings such as barbed wire fence appearance of ridges and furrows, fluffy cotton ball appearance of hypopigmented perifollicular lesions and sprinkled pepper appearance of pigmented dispersion. Out of the 115 KOH mount positive cases, 51 (44.3%) showed growth on fungal culture with Malassezia furfur being the most common species to be isolated in 18 patients.

Conclusions:

Dermoscopy is a new, popular non-invasive diagnostic modality, which shows specific features like fine scaling, pigment alteration, ridges and furrows with perifollicular involvement, and can be used to diagnose doubtful cases of PV as an adjunct or substitute to a KOH mount.

Introduction

Pityriasis versicolor (PV) is a mild, superficial fungal infection caused by the Malassezia species. It affects the stratum corneum layer of the skin leading to discoloured patches, mostly seen over the chest, back and extremities.[1,2] The term ‘Pityriasis’ refers to scales like bran and ‘versicolor’ meaning varied colours. The term ‘tinea versicolor’ is actually a misnomer. A few synonyms for this condition include dermatomycosis furfuracia, chromophytosis, tinea flava and liver spot.[3] PV is mostly seen in hot, humid areas and temperate climates. A few predisposing factors are excessive sweating, diabetes mellitus, Cushing’s disease, immunosuppression and malnourishment.[3,4] The genus Malassezia includes a group of dimorphic fungi that occurs as normal flora on the human skin. It is usually associated with mild superficial infection, but in immunocompromised patients, it is now emerging as an opportunistic fungal pathogen. Although it is an asymptomatic infection, the ensuing pigmentary changes can be cosmetically distressing to the patient. Clinically, it is characterized by discrete or confluent hypopigmented or hyperpigmented macules with fine brawny scaling, with a positive scratch test eliciting a ‘coup d’ongle sign’. The diagnosis is mostly clinical due to its characteristic appearance; it is aided by orange-yellow fluorescence on woods lamp and spaghetti and meatball appearance on potassium hydroxide (KOH) mount.[5,6]

Dermoscopy, a non-invasive modality, is emerging as a useful tool in the diagnosis of various conditions. Literature regarding the dermoscopic features of PV is limited. Hence, this study was undertaken to describe the various dermoscopic patterns of hypopigmented and hyperpigmented lesions of PV. Fungal culture in versicolor is seldom used as an adjunct in diagnosis, thus the culture findings are rarely studied. We studied the culture characteristics of PV to identify the prevalent species and growth patterns in our geographical area.

Even though there is a disparity in the geographical distribution of different species, little data is available from the studies conducted in our country. Hence this study was taken up to identify the various clinical patterns with respect to morphology and distribution and associated risk factors, to describe the various dermoscopic patterns and to analyse the distribution of various Malassezia species in PV infection.

Materials and Methods

This was a cross sectional, hospital-based study conducted for 12 months. All clinically suspected cases of PV of all age groups were included and subjected to a KOH mount examination. On confirmation of the microbiological diagnosis, informed consent was obtained and a total of 115 patients were recruited in the study. Patients who had a history of intake of oral antifungals and application of any topical creams were excluded. Demographic details were obtained followed by a detailed clinical examination.

Dermoscopic evaluation was performed using white light dermoscopy (Dermlitefoto attached to Canon G15) without a contact medium and images were obtained. The scales for fungal culture were obtained and tested in the laboratory and the results were obtained after 3 weeks. Statistical analysis was done using SPSS software version 21. Ethics approval obtained, dated 02.12.2020.

Results

Among the 115 participants, 67 (58.1%) were males and 48 (42.7%) were females. The minimum age in the study group was 1 year and the maximum age was 71 years. The mean age was 30.21 years.

On clinical evaluation, 43 (37.4%) of the patients had involvement of only one body part. The remaining 72 (62.6%) of the patients had multiple site involvement. The most frequently involved sites were the back (47.8%) followed by the face (30.4%) and upper limb (27.8%). The least involved body part was the groin (2.6%). Hypopigmented lesions (79, 68.7%) were found to be the most common type. Other forms like hyperpigmented (31, 27%) and erythematous (4, 3.4%) were also noted. Only 1 (0.9%) patient had both hypopigmented and hyperpigmented lesions. Annular morphology was noted in 68 (59.1%) patients. Polycyclic lesions were seen in 32 (27.8%), and 15 (13.1%) patients had lesions with irregular shapes [Figure 1]. In this study, 58 (50.4%) of the patients presented with macules, 25 (21.8%) with patches, 9 (7.8%) with follicular lesions and 23 (20%) had mixed phenotype of macules, patches or follicular arrangement. The most common pattern was follicular lesions along the border of macules and patches.

Figure 1.

Varied clinical presentations of Pityriasis Versicolor in various part of the body in pigmented skin. (a) Hypopigmented macules of pityriasis versicolor over right mandibular area and neck of a child. (b) Multiple large Hypopigmented coalescing macules and patches noted over neck and back of a middle aged male. (c) A large velvety scaly plaque noted over right axilla in a middle aged female. (d) single large ill-defined hyperpigmented plaque resembling velvety lesion in a middle aged female patient

Sweating was found to be the most commonly associated risk factor for the development of PV in both chromic and achromic types. The other associated factors were the concurrent presence of seborrheic dermatitis in 8.7% of the individuals. A positive family history was noted among 18 (15.7%) of the patients, mostly among individuals living in the same household.

On woods lamp examination, 76 (66.1%) of the patients showed fluorescent lesions, whereas 39 (33.1%) of the patients showed non-fluorescent lesions. The dermoscopic features of PV were categorized into the following domains such as scaling, pigmentation and other features [Table 1]. Scaling was noted in 88.7% of the patients. Among them, patchy scaling was noted in 80 patients, diffuse scaling was seen in 14 patients, 8 patients had perifollicular scaling and 8 patients had peripheral scaling. Pigmentary changes were noted in all the patients. Non-uniform pigmentation was noted in 73.9% of patients and perilesional pigmentation was seen in 26.1% of the patients. Ridges and furrows were seen in 7.8% of the patients.

Table 1.

Dermoscopic features of pityriasis versicolor

	No. of cases (n=115)	Percentage
(a) Scaling	102	88.7
Diffuse	14	12.1
Patchy	80	69.6
Perifollicular	8	6.9
Peripheral	8	6.9
(b) Pigmentation	115	100
Non-uniform pigmentation	110	95.6
Perilesional pigmentation	30	26
(c) Ridges and Furrows	9	7.8
(d) Margins	115	100
Well-defined borders	19	16.5
Ill-defined borders	96	83.5

A few new features were noted such as ‘cotton candy appearance’ of hypopigmented follicular lesions, ‘barbed wire fence appearance’ of scaling over ridges and furrows, ‘sprinkled pepper appearance’ of pigment dispersion, ‘fluffy cotton ball appearance’ of hypopigmented discrete lesions with irregular margins and ‘starry sky appearance’ of hypopigmented satellite lesions [Figures 2–6].

Figure 2.

Dermoscopy (original magnification 10x) of a Hypopigmented lesion showing non-uniform pigmentation, perilesional hyperpigmentation, radial distribution of the lesion from hair follicle and satellite lesions

Figure 6.

Dermoscopy (original magnification 10x) of a Hyperpigmented lesion showing pigment dispersion like sprinkled pepper appearance

Figure 3.

Dermoscopy (original magnification 10x) of a Hypopigmented lesion showing well defined borders, perilesional hyperpigmentation and furrows with cotton candy appearance

Figure 4.

Dermoscopy (original magnification 10x) of a Hyperpigmented lesion showing prominent scaling in the furrows resembling Barbed wire fence

Figure 5.

Dermoscopy (original magnification 10x) of a Hypopigmented follicular lesion showing perifollicular hypopigmentation resembling Fluffy cotton ball

Out of 115 KOH mount positive cases of PV, 51 (44.3%) had growth on fungal culture. Out of 51 isolates, Malassezia furfur was the most common species to be isolated in 18 patients (35.2%), followed by Malassezia globosa in 11 patients (21.6%), Malassezia obtusa in 10 patients (19.6%), and Malassezia pachydermatis and Malassezia sympodialis in 6 patients each (11.8%).

Discussion

In our study, the age group most commonly affected was 21–30 years, including 31 (27%) patients, followed by 11–20 years, which included 28 (24.3%) patients. This is in accordance with other studies, in which 30 and 32% of those affected with PV belonged to the age group of 21–30 years.[5,7] In another study, 22.5% of the affected patients belonged to the age group 11–20 years.[6] This can be attributed to increased sebum production in adolescents and body consciousness in this age group.

In this study, male patients (67, 58.1%) were more commonly affected than female patients (48, 42.7%). A greater prevalence of PV was also noted in a study in 2008, in which they observed the percentage of affected males was 59.01% and affected females was 40.9%.[8] However, in contrast, a study done in Argentina found females (63%) to be more affected than males (37%), attributing it to extra attention to beauty by women.[9] A higher prevalence in males in our study could be due to increased physical activity and outdoor activities leading to increased sun exposure and sweating favouring the growth of an organism.

Various predisposing factors have been described in the development of PV. In our study, 42.6% of the patients noticed increased sweating, with summer aggravation observed in 24.3% of the patients. A similar finding was noted in other studies done in similar weather conditions, attributing the growth of fungi in higher temperatures, tropical climates and humidity.[7,10]

Seborrheic dermatitis was found to coexist in 10% of the patients in a study,[8] in concordance with findings in our study with 8.7% prevalence. This can be ascribed to identical causative agents and predisposing factors in both conditions. A positive family history was noted in 15.7% of the patients in our study, which is comparable to findings by Sharma et al.[6] with 16.8%. A hereditary predisposition has not been described in the pathogenesis.

In this study, the major site of involvement was the back (47.8%), followed by the face (30.4%). This is similar to findings in other studies with 48% of patients with lesions on the back.[11] Increased sebaceous glands in these regions can be the reason for the involvement of these areas in PV. Achromic types of PV lesions (68.7%) were more commonly noted in this study as compared to the chromic type of lesions (31.3%). This correlates with Snekavalli et al.,[11] Rao et al.[5] and Kabbin et al.[12] findings, who reported achromic lesions in 68, 75 and 67%, respectively.

Woods lamp as a diagnostic aid was positive in 66.1% of our patients. A slightly higher proportion was found in studies with 88.4 and 86%.[13,14] Thus, it can be used as an effective adjunctive diagnostic modality in doubtful cases of PV where laboratory facilities are not available.

Dermoscopy is not routinely used in the diagnosis of PV; hence very few findings have been previously described. In our study, scaling on dermoscopy was noted in 102 (88.7%) of the patients. In concordance with our study in 2019,[15] scaling on dermoscopy in 86.5% of the patients was also reported. Pigmentary changes were noted in all the patients. Non-uniform pigmentation was noted in 94.9% of patients with achromic lesions and 100% of patients with chromic lesions. Perilesional pigmentation was seen in 37.9% of the patients. These findings are in concordance with the previous study,[15] which reported non-uniform pigmentation in 92.6% of patients with achromic lesions and 100% of chromic patients. Perilesional pigmentation was reported in 34.1% of patients.

Vascular patterns like linear branching vessels and dotted vessels, reported by Mathur et al.,[16] were not seen in our study. As Malassezia involves the superficial layer of the skin, primary vascular involvement is unlikely.

Another study on dermoscopic analysis of versicolor revealed an altered pigmentary network (100%) as the most common finding, followed by scaling (83.3%).[16] These findings are similar to our study. They also observed a folliculocentric pattern seen in our study as well. The contrast halo ring was not seen in our study. Differences in findings among the studies could be attributed to intra-operator variability and experience. Scaling and pigmentary changes were the consistent features noted among all studies. In addition, we have described a few new findings that can aid in diagnosis in the future.

Growth in fungal culture was seen in 44.3% of the patients. Out of 51 isolates, M. furfur was the most common species isolated in 35.2% of culture-positive PV cases, followed by M. globosa in 21.6%, M. obtusa in 19.6%, M. pachydermatis and M. sympodialis in 11.8%. Similar findings were noted in a study,[12] where 46% of the patients had growth on a fungal culture. In contrast to our study, Snekavalli et al.[11] reported 76% growth on fungal culture with the most common isolate being M. globosa (48.7%) followed by M. sympodialis (25%), M. furfur (10.5%) and M. restricta (7.9%). The variation in sampling techniques and use of different culture media such as SDA with olive oil overlay, modified Dixon’s agar, and Leeming and Notman agar may be the cause for different isolation rates in various studies. The tropical climate is associated with increased sweating, and due to this, scaling may be a less common presenting feature. This could probably be the cause for the low yield on culture.

Limitations

It was a hospital-based study, hence there may be more findings noted in the general population. Most of the patients had skin type of Fitzpatrick IV or V, and other skin types may have varying findings. The area where the study was conducted has humid weather, hence scaling may not be very apparent due to sweating. Dermoscopic evaluation is based on experience by the operator, hence findings may vary.

Conclusion

PV is a common dermatological condition characterized by discoloured lesions of the skin. Woods lamp and KOH have traditionally been used to aid in the diagnosis. Currently, dermoscope which is a non-invasive modality, and gaining wide popularity, can be used to diagnose difficult cases. Our study confirms that dermoscopic evaluation is an effective modality in aiding in the diagnosis of PV. As compared to other modalities, KOH mount is found to be the most sensitive modality in the diagnosis of PV as compared to woods lamp, fungal culture and dermoscopy.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

IADVL.