Prinz Vavricka BM, Trüeb RM
Department of Dermatology, University Hospital Zurich, Switzerland

A six year old girl, with normal physical and mental development, presented with unruly hair acquired since the age of four. Her personal history was unremarkable: she had not suffered any systemic illness, and had no history of drug intake. No other members of the child's family were affected. Clinical examination revealed that the scalp hair consisted of two hair populations intermingled: the first, normal type was characterized by straight, long, normally pigmented shafts. Shafts of the second, abnormal type were short, wavy, hypopigmented and lustreless. The following investigations were normal: serum iron, ferritin, basal TSH, fT3 and fT4. Direct examination of the hairs with light microscopy revealed that abnormal hairs were thinner than the normal ones and presented irregular torsions. The proportion of normal hairs to abnormal hairs was 72% to 28%. Taken together, the clinical and microscopic findings were characteristic for diffuse partial woolly hair (DPWH). First described in 1987 by Ormerod et al, DPWH represent a distinct entity within the woolly hair spectrum. It is a rare disorder that is seen either sporadic or familial, usually starting in childhood or young adulthood. Most patients are female. The characteristics of the disorder are two different hair populations: normal straight hair interspersed with woolly hair in a diffuse manner. The straight hairs are predominant (70-80%). With higher percentages of woolly hair, the scalp hair may appear thinned. The differential diagnosis includes woolly hair, acquired progressive kinking of the hair, and acquired partial curly hair. The cause of the disorder remains elusive, and there is no specific treatment recommendation.