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 65 year-old man had developed multiple, scattered, itchy excoriated erythematous papules on both arms starting 2 years prior. He had no underlying disease. The biopsied skin lesion showed hyperkeratotic epidermis with acanthosis. Elongated and irregular rete ridges were observed. The final diagnosis was prurigo. He was treated with oral cyclosporine (25 mg/day) and naltrexone (50 mg/day), and there was no improvement in the symptoms within 2 years. Therefore, the oral alitretinoin treatment (30 mg/day) was started. After 3 weeks of alitretinoin treatment, the patient achieved partial remission. The skin lesions and itching sensation were improved and the patient stopped medical treatment.