Pachyonychia congenita: a clinical study of 12 cases and review of the literature.

Twelve cases of pachyonychia congenita were reviewed. The mode of inheritance was autosomal dominant. The clinical features of these patients included thickened nails, hyperkeratosis of the palms and soles, thinning of hair or alopecia, painful bullae or ulcerations of the palms and soles, leukokeratosis oris, verrucous lesions of the extremities, hyperhidrosis, premature eruption of teeth, paronychial infections, epidermal cysts with milia, and corneal dyskeratosis at times associated with cataracts. Biopsy from the plantar lesions usually revealed marked hyperkeratosis, acanthosis, moderate hypergranulosis, and minimal dermal inflammatory infiltration. Treatment with keratolytic agents and lubricants is indicated to areas of palmar and plantar hyperkeratosis but usually produces only transient benefit. Squamous cell carcinoma developed in one of the patients over the site of chronic plantar ulcerations. Areas of chronic bullous formation or ulceration should be observed for possible skin malignancy.