[Constitutional painful callosities. Analgesic efficacy of etretinate]

We have recently evaluated eight patients with an unusual genetic dermatosis that was characterized by the development of painful callosities at pressure points of soles, with tender yellowish-brown hyperkeratosis. These lesions are very painful: walking produced pain that was severe. The patients performing manual labor, in addition, had multiple callosities on the palms. Hyperhidrosis of the soles and palms was frequently present. Skin lesions were first noted in adolescence. There was no similar family history. There was no personal nor family history of hair, nail or dental disease. A biopsy was performed in one case and showed a simple hyperkeratosis similar to these observed in callosities. Classification of our cases is difficult. They are not similar to the entity named "hereditary painful callosities" by Roth et al. Review of the literature did not show similar cases. The patients received Etretinate (1 mg/day/kg). In all 8 cases, a dramatic improvement was obtained within seven days; the pain disappeared entirely and the patients were able to walk again without any pain. Then, the per-day dose was diminished without reappearance of the pain.