A 56 year-old man presented with 2 year-old, itchy, erythematous to brownish papules with silver scales on both legs. He had hypertension and diabetes mellitus. The clinical diagnosis was prurigo nodularis and punch biopsy was done. Microscopic examination showed a pronounced granular layer and numerous lymphocytic infiltrations of the papillary dermis with mild spongiosis (c). The final diagnosis was Kyrle’s disease with prurigo nodularis. He was treated with cyclosporin (100 mg/day) and narrowband ultraviolet-B(NB-UVB) twice/week for 12 weeks. However, there was no improvement of symptoms. Therefore, oral alitretinoin (30 mg/day) was started. After 16 weeks of treatment, skin lesions and pruritus were improved. His score on the visual analog scale for pruritus improved (from 6 to 3). His treatment with oral alitretinoin continued for 19 months and he successfully achieved complete remission without recurrence.
A 75 year-old man presented with multiple scattered nodules and excoriated patches with crusts on the trunk, both arms, and both legs that were two weeks old. He had no underlying disease. The initial clinical diagnosis was prurigo nodularis and treatment was started. Despite treatment with oral cyclosporine (100 mg/day) for 3 years, his symptoms and skin lesions waxed and waned. After that, the treatment was changed to oral alitretinoin in a dose of 30 mg/day. Within 12 weeks of treatment, pruritus had improved and treatment with oral alitretinoin was stopped with partial remission.