Acquired partial curly hair.

We report 6 adolescent females apparently affected by diffuse partial woolly hair. The patients complained of thinning and curling of some hair of the scalp. Examination revealed two distinct hair populations. The first hair population was straight, normally pigmented and of normal length, thus considered "normal" hair. The second hair population was wavy, curly, thinner and apparently slightly shorter, thus considered abnormal. Direct examination of the abnormal hair population under a light microscope revealed a curled pattern of the hair shaft, and single torsions. With light microscopy the clinically normal hair had no abnormalities. Under scanning electron microscopy (SEM) the abnormal hair had curly and flattened hair shafts of 30-60 mum in diameter, oval shaped sections, canalicular formations, single torsions and cuticular weathering. With SEM, clinically "normal" hair had a diameter between 60-80 mum, with no major relevant abnormalities except for weathering. These results are suggestive of a new variant of acquired kinking (curling) of hair simulating diffuse partial woolly hair. The absence of clinical alterations in the proximal area of the affected hair and the spontaneous improvement with time, suggests that this variant may result from environmental exposure (weathering, cosmetic procedures) in predisposed individuals.