Pityrosporum folliculitis (PF) is a polymorphic dermatomycosis characterized by the development of multiple follicular papules and pustules. This disease occurs mainly in the seborrheic areas of the face, back and chest. Being aggravated by hot weather and sweating, PF has shown to be a common disease in the tropics. Clinically, it may present similarly as other diseases such as acneiform drug eruption. Differentiation between these two disease entities and an objective method of ruling out PF are important in our setting as management will differ. We report a case of pityrosporum folliculitis in a patient who had a history of chronic oral steroid intake and presented clinically with an acneiform eruption on his face, chest and back. Microscopy and skin biopsy revealed the presence of Pityrosporum. The patient was successfully treated with systemic and topical anti-fungal medications. We postulate that in this patient, immunosuppression due to exogenous steroids may be the predisposing factor for pityrosporum folliculitis. Since acneiform drug eruption and pityrosporum folliculitis may present similarly, misdiagnosis is common. We suggest that when presented with an acneiform eruption in an immunosuppressed patient, direct microscopy of KOH mounts of lower comedonal

Human ; Male ; Adult ; Acneiform Eruptions ; Biopsy ; Causality ; Dermatomycoses ; Diagnostic Errors ; Drug Eruptions ; Folliculitis ; Malassezia ; Skin ; Sweating ; Weather

A 21 year old Filipino male presented with swelling of the second right hand digit unresponsive to antibiotics. Amputation revealed chronic inflammation and negative cultures. He developed sterile conjunctivitis and a generalized eruption of asymptomatic red papules and nodules. First skin biopsy revealed a diffuse infiltrate of epithelioid and foamy histiocytes, diagnosed as "juvenile xanthogranuloma." The second biopsy revealed large histiocytes with a "ground-glass" eosinophilic cytoplasm, multinucleated giant cells, and mixed cell infiltrate. Immunohistochemistry showed histiocytes staining with (+)S100 and (+)CD68, and (-)CD1a. Final diagnosis was "multicentric reticulohistocytosis." Despite treatment with oral prednisone, methotrexate and alendronate, lesions were progressive.
CONCLUSION: This fascinating case manifests with overlapping features of both juvenile xanthogranuloma and multicentric reticulohistiocytosis, and lead the authors to suggest considering the spectrum of diseases called the non-Langerhans cells histiocytosis when presented with a generalized nodular eruption.

Human ; Male ; Young Adult ; Antigens, Cd1 ; Biopsy ; Conjunctivitis ; Exanthema ; Giant Cells ; Histiocytes ; Histiocytosis, Non-langerhans-cell ; Inflammation ; Methotrexate