Hypotrichosis and nail dysplasia: a novel hidrotic ectodermal dysplasia.

We report a unique isolated hair and nail ectodermal dysplasia in a 3-year-old girl. Clinical examination revealed short, sparse scalp hair, absent eyebrows, short eyelashes and nail dystrophy in all digits. Nail changes included shortened nail plate with distal onycholysis and loss of the cuticle. Sweating and teeth were normal. Development was normal. Scanning electron microscopy of the hair only demonstrated trichorrhexis nodosa. There was no pili torti. Vertically sectioned scalp biopsy revealed hypoplastic hair follicles and a horizontally sectioned biopsy showed a decrease in the overall number of hair follicles present. Treatment with topical minoxidil 5% 1 mL twice each day massaged into the scalp led to only minimal improvement and was discontinued after 12 months.