Clinico epidemiological study of pityriasis alba

Even though pityriasis alba is commonly encountered in dermatological practice, there is paucity of Indian studies on the subject. A clinico epidermiological study was carried out in 200 patients attending the skin department of Command Hospital, Air Force, Bangalore. Atopic background was detected in 85.5% of cases. Bacterial and fungal culture studies failed to reveal any infective aetiology. Helmenthiasis and iron deficiency anaemia were detected in 15.5% and 16.5% of patients respectively. However no other nutritional deficiency was observed in the present study. Majority (84.5%) of patients had lesions of less than 6 months duration at the time of presentation. Face was involved in 91% of patients and generalized pityriasis alba was observed in 3 patients, all of them being infants. Pigmenting pityriasis alba was observed in 7 patients. Hyperkeratosis, parokeratosis, acanthosis, spongiosis and perivascular infiltration were the consistent histological features of pityriasis alba.