A 61 year-old man presented with several one month-old erythematous to brownish papules and nodules on the back and both legs (a,c). He had diabetes mellitus. The initial clinical suspicion was prurigo nodularis and punch biopsy was done. Microscopic examination showed hyperkeratotic epidermis with acanthosis and parakeratosis. Elongated and irregular rete ridges were observed with dense dermal perivascular infiltration (a,b). The final diagnosis was prurigo nodularis. Initially, he was treated with oral cyclosporine 100 mg/day for 4 weeks. However, relief of the symptoms was insufficient and oral alitretinoin was started at a dose of 30 mg/day. After 4 weeks of alitretinoin treatment, symptoms and skin lesions were improved, and with 8 weeks of treatment (b,d), he stopped medical treatment and achieved complete remission without recurrence.
A 78 year-old man diagnosed with prurigo nodularis had itchy multiple erythematous to brownish papules on both flanks, chest, and back that were 6 months old. He had no underlying disease. Oral cyclosporine (50 mg/day) was taken for 1 year. His symptoms waxed and waned. In our study, oral alitretinoin (30 mg/day) was started. Within 2 weeks of treatment, the skin lesions and pruritus had improved. The patient was treated with oral alitretinoin for 14 weeks until complete remission and then the treatment was stopped without recurrence.