Psoriasis occurring in lamellar ichthyosis: response to Epilyt.

Psoriasis occurring in a patient with lamellar ichthyosis is reported. Similar self-limited episodes had occurred earlier. On histopathologic examination of a biopsy specimen, an eruptive plaque showed parakeratosis and a reduction in the granular layer. Electrophoretic analysis of the keratins isolated from the epidermis of a plaque showed a reduction in the amount of the 67 kd polypeptide compared to the keratins of ichthyosis epidermis. Both of these findings support the diagnosis of psoriasis. Epilyt, applied daily, was effective in removing scales.