A case of unilateral Darier's disease

A 66-year-old man presented with red-brownish hyperkeratotic papules along Blaschko's lines on the left side of the trunk as well as the left upper and lower extremities. There were no other lesions on the skin, mucosa, or nails. The patient did not complain of any worsening of the symptoms during the summer. A previous treatment with topical steroids was ineffective. A skin biopsy of the keratotic papule obtained from the epigastrium showed irregular hyperkeratosis, a suprabasal cleft with several acantholytic cells, and dyskeratosis in the form of corps ronds in the epidermis. Based on the clinical and histological findings, we diagnosed the patient as having unilateral Darier's disease. Topical Vitamin D₃ was not effective. Upon the administration of systemic etretinate and topical adapalene, the hyperkeratotic papules became flattened but persisted.