The epidemiology of Malassezia (Pityrosporon) folliculitis in Singapore

Clinical characteristics and treatment outcomes of Pityrosporum folliculitis in immunocompetent patients

Pityrosporum folliculitis (PF) is a fungal acneiform disease of the hair follicles that often presents with pruritic papules and pustules on the upper body and face. This condition is commonly mistaken for acne vulgaris and can be distinguished from bacterial acne by the presence of fungal spores in the follicular lumen. Although studies have been performed to describe PF in cohorts, little work has been done to aggregate these data. Thus, the goal of this review is to describe the clinical characteristics and treatment outcomes of PF in immunocompetent patients. PubMed, Web of Science, and Embase were searched using the terms "Pityrosporum folliculitis" or "Malassezia folliculitis." All cohorts reporting PF characteristics in patients classified as immunocompetent were reviewed. A total of 15 studies were included. Majority of patients were male (64%) with the average age of presentation of 24.26 years. The most common locations of lesions were the chest (70%) and back/shoulders (69.2%). Pruritus was reported by the majority of patients (71.7%). Additionally, 40.5% of patients reported a history of unsuccessful treatment regimens. Treatment was most successful with an oral antifungal (92%), followed by a topical antifungal (81.6%). In conclusion, majority of patients with PF were younger males. Many patients were primarily treated incorrectly, suggesting the importance of proper diagnosis. PF may be distinguishable from acne vulgaris by the presence of pruritus or suggested when a new acneiform eruption develops following antibiotic therapy or immunosuppression. When properly diagnosed, majority of cases of PF achieve complete response with oral or topical antifungals.

Critical synthesis of available data in Malassezia folliculitis and a systematic review of treatments

Folliculitis is an inflammatory process involving the hair follicle, frequently attributed to infectious causes. Malassezia, an established symbiotic yeast that can evolve to a skin pathogen with opportunistic attributes, is a common source of folliculitis, especially when intrinsic (e.g. immunosuppression) or extrinsic (high ambient temperature and humidity, clothing) impact on the hair follicle and the overlying skin microenvironment. Our aim was to critically review the pathophysiology and clinical characteristics of Malassezia folliculitis, to describe laboratory methods that facilitate diagnosis and to systematically review treatment options. Malassezia folliculitis manifests as a pruritic, follicular papulopustular eruption distributed on the upper trunk. It commonly affects young to middle-aged adults and immunosuppressed individuals. Inclusion into the differential diagnosis of folliculitis is regularly oversighted, and the prerequisite-targeted diagnostic procedures are not always performed. Sampling by tape stripping or comedo extractor and microscopic examination of the sample usually identifies the monopolar budding yeast cells of Malassezia without the presence of hyphae. However, confirmation of the diagnosis with anatomical association with the hair follicle is performed by biopsy. For systematic review of therapies, PubMed was searched using the search string "(malassezia" [MeSH Terms] OR "malassezia" [All Fields] OR pityrosporum [All Fields]) AND "folliculitis" [MeSH Terms] and EMBASE was searched using the search string: 'malassezia folliculitis.mp OR pityrosporum folliculitis.mp'. In total, 28 full-length studies were assessed for eligibility and 21 were selected for inclusion in therapy evaluation. Conclusively Malassezia folliculitis should be considered in the assessment of truncal, follicular skin lesions. Patient's history, comorbidities and clinical presentation are usually indicative, but microscopically and histological examination is needed to confirm the diagnosis. Adequate samples obtained with comedo extractor and serial sections in the histological material are critical for proper diagnosis. Therapy should include systemic or topical measures for the control of the inflammation, as well as the prevention of recurrences.

An update on pityrosporum folliculitis in Singapore from a single tertiary care dermatological centre

INTRODUCTION

Pityrosporum folliculitis (PF) is a common skin condition that can be misdiagnosed, especially by non-dermatologists. While the diagnosis is often made clinically, skin microscopy may be used to confirm the same. There is scant literature on the clinical epidemiology of PF globally. In Singapore, to our knowledge, one prior epidemiological study was performed in 1987. We aimed to provide an update regarding the epidemiology, diagnosis and treatment of patients with PF in Singapore.

METHODS

We performed a retrospective review of patients with clinical presentations compatible with PF, who presented to the National University Hospital dermatology clinic, Singapore, between 1 January 2011 and 31 December 2015. The medical records of patients identified as having clinical presentations that resembled PF were reviewed via the hospital written and electronic databases. Information was collected on their demographics and clinical presentation.

RESULTS

Of 375 patients identified, 214 (57.1%) patients were confirmed to have PF on Gram-stained microscopy. Of these 214 patients, most patients were in the age group 21-30 years (35.0%). The male-to-female ratio was 3:1. The lesions predominantly occurred on the trunk and back. A majority of patients presented with symptom duration over one month. 128 patients received oral antifungal treatment (59.8%), whereas 82 patients were treated with topical antifungal treatment alone (38.3%).

CONCLUSION

The typical Singapore patient with PF is a young man in the age group 21-30 years, with erythematous follicular papules or pustules over the trunk and back.

Comparison between Malassezia Folliculitis and Non-Malassezia Folliculitis

Background

Among the various types of folliculitis, differentiation of Malassezia folliculitis (MF) from other forms of folliculitis is important because it is usually treated with antifungal agents.

Objective

We attempted to find a method to enhance the detection rate of MF, and examined the differences in the clinical manifestation between MF and non-MF (NMF).

Methods

We performed a retrospective study involving patients with folliculitis who were previously diagnosed with MF or NMF on the basis of serial tissue sectioning and diastase-Periodic acid-Schiff (d-PAS) staining findings. The clinical features of MF and NMF were compared.

Results

Among a total of 100 folliculitis patients, 20 were diagnosed with MF and 80 with NMF. Tissues from the 80 patients with NMF were sectioned serially into 10 slices and stained with hematoxylin and eosin stain; among these, 10 had many round-to-oval yeast organisms in the hair follicles that confirmed MF. Finally, d-PAS staining was used to detect the presence of yeast in the NMF slides. Notably, among the 70 d-PAS-stained samples, yeast organisms were found in 6 samples, confirming MF. As a result, the diagnosis of 16 patients changed from NMF to MF. Compared with NMF, MF showed major involvement of the trunk and low involvement of the face and legs as well as male predilection.

Conclusion

Physicians should consider serial sectioning and/or d-PAS staining of folliculitis lesions, particularly of those on the trunk of male patients, even if no yeast organisms are detected initially.

Malassezia folliculitis is caused by cutaneous resident Malassezia species

Malassezia folliculitis [MF] is caused by the invasion of hair follicles by large numbers of Malassezia cells, but it remains unclear which Malassezia species are involved in the disease. To clarify this situation, Malassezia species isolated from lesions of MF patients were analyzed by both culture and non-culture methods. In addition, Malassezia species recovered from the non-lesion areas of the skin of MF patients and skin samples of healthy subjects were included in this study. The test population consisted of 32 MF patients and 40 healthy individuals. The lesions were obtained using a comedone extractor, while swabs were employed to obtain skin samples from non-lesion areas of the patients and healthy subjects. Malassezia DNA was analyzed using a real-time PCR technique. The detection limit of the culture method was 5 CFU/cm(2) as opposes 50 cells/cm(2) with non-culture procedures. The predominant species recovered from MF lesions were M. globosa and M. sympodialis by culture method analysis, and M. restricta, M. globosa, and M. sympodialis with non-culture methods. These results were in agreement with those found with samples from non-lesion skin areas of MF patients and healthy subjects. This study clarified that MF is caused by Malassezia species that are part of the cutaneous microflora and not by exogenous species.

[Malassezia folliculitis: characteristics and therapeutic response in 26 patients]

BACKGROUND

Malassezia folliculitis is most often described in patients living in hot and humid countries or in immunocompromised patients. Its frequency in France is unknown. We report 26 cases diagnosed at Saint-Louis Hospital between May 2002 and April 2004. The clinical features, the contributing factors, the results of direct mycological examination and/or histology and the efficacy of antifungal treatments were compared to the literature.

PATIENTS AND METHODS

The inclusion criteria were the presence of folliculitis on the trunk confirmed by direct microscopy and/or histopathology showing abundant yeast cells in the follicles.

RESULTS

Patients comprised 22 men and 4 women (M/F sex ratio: 5: 5) with a mean age of 46 years. Five patients (19%) were immunocompromised. In normal patients, the duration of folliculitis was long with a mean of 61 months. The eruption was typical, with follicular papules and superficial pustules distributed predominantly on the trunk. Itching was frequent (70%). Direct microscopy was more often positive than histology (89% vs 33%). Some sixty-five percent of the patients had been previously treated by topical or systemic antibiotics or anti-acne drugs, which was ineffective in all cases. Cure with topical ketoconazole, oral ketoconazole alone or in combination with topical ketoconazole occurred respectively in 12%, 75% and 75% of patients, but with consistent recurrence within 3 to 4 months after cessation of treatment.

DISCUSSION

Malassezia folliculitis is probably misdiagnosed, as suggested by the long time between onset and diagnosis and the high frequency of non-antifungal treatments prescribed. In our study, direct mycological examination provided more effective diagnosis than histology. Treatment is difficult especially because of the high frequency of relapses.

CONCLUSION

A diagnosis of Malassezia folliculitis should be considered in young adults or immunocompromised patients with an itching follicular eruption. Further therapeutic trials are needed due to the frequency of relapse.

Skin diseases associated with Malassezia species

The yeasts of the genus Malassezia have been associated with a number of diseases affecting the human skin, such as pityriasis versicolor, Malassezia (Pityrosporum) folliculitis, seborrheic dermatitis and dandruff, atopic dermatitis, psoriasis, and--less commonly--with other dermatologic disorders such as confluent and reticulated papillomatosis, onychomycosis, and transient acantholytic dermatosis. Although Malassezia yeasts are a part of the normal microflora, under certain conditions they can cause superficial skin infection. The study of the clinical role of Malassezia species has been surrounded by controversy because of their fastidious nature in vitro, and relative difficulty in isolation, cultivation, and identification. Many studies have been published in the past few years after the taxonomic revision carried out in 1996 in which 7 species were recognized. Two new species have been recently described, one of which has been isolated from patients with atopic dermatitis. This review focuses on the clinical, mycologic, and immunologic aspects of the various skin diseases associated with Malassezia. It also highlights the importance of individual Malassezia species in the different dermatologic disorders related to these yeasts.

Pityrosporum folliculitis in the Philippines: diagnosis, prevalence, and management

Sixty-eight typical cases were studied to define the course of Pityrosporum folliculitis in a tropical setting. Contrary to reports in the literature, we found Pityrosporum folliculitis to be polymorphic. The "molluscoid" comedopapule was the most characteristic and common lesion, and it yielded consistently high spore counts. The face was commonly involved. To establish the diagnosis, we used direct microscopy of potassium hydroxide/Parker blue-black ink mounts of the lower poles of comedonal plugs. Pityrosporum folliculitis is common in the Philippines, although our adult controls had a low incidence of skin carriage of Pityrosporum orbiculare on the face compared with those reported in the West. Pityrosporum folliculitis coexisted with acne vulgaris in 56% of patients, and the addition of antimycotics to the acne regimen produced dramatic clearing of lesions.