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 54 year-old man presented with multiple, 1 month-old, itchy erythematous maculopapular patches on both legs, both arms, and back, which were diagnosed as prurigo nodularis. He had no underlying disease. Treatment with oral cyclosporine (50 mg/day) was started. However, his blood pressure exceeded the hypertension borderline after 8 weeks of treatment even though he had no underlying hypertension. Therefore, the treatment was changed to oral alitretinoin (30 mg/day) for 2 weeks. His itching sensation was reduced after the treatment without recurrence.