mycological study of seborrheic dermatitis

ABSTRACT

Seborrhoeic dermatitis is a chronic superficial disease of the skin. The histologic picture is not diagnostic, it is half- way between psoriasis and chronic dermatitis. The cause is unknown. Of 190 patients and 20 controls, it was found that the highest age incidence [12-20y] [41.1%]. Familial tendency, obesity and winter aggravation are the most important predisposing factors. Direct microscopy of the KOH clearing is not a fruitfully diagnostic method. Culture on Dixon's medium or SDCCA without fermentative assay is sufficient to diagnose the presence of P. ovale. The tape - count method showed that the Seborrhoeic lesions were highly colonised by P. ovale and the patients have tendency to be more colonised by the yeast than healthy controls. Eradication of the yeast and dandruff by ketoconazole shampoo improves the lesions and prevents recurrence for 3 months after treatment. The presence of the yeast was associated with late- onset skin reaction and delayed skin reaction against two prepared antigens of P. ovale, corpuscular and crude coca extract antigens in [18.8%, 8.3%] of patients