Clinicopathologic study on pityriasis alba.

Pityriasis alba (PA) is a relatively common skin disorder usually seen in children and young adults characterized by the presence of superficial hypopigmented macules. A clinicopathologic study on pityriasis alba was undertaken which showed an increased occurrence of the disease in preadolescent children with an equal incidence in boys and girls, and a predominance of white over black patients. There was an increased personal history of atopy and the skin lesions were found to occur most frequently in the arms and face followed by the legs and the trunk. Histologic evaluation of biopsy specimens of PA showed consistent spongiosis, follicular spongiosis, focal parakeratosis and acanthosis in the epidermis together with a superficial perivascular lymphocytic infiltrate.