A 54 year-old man had developed several scattered, itchy, excoriated erythematous papules on both the arms and back (5 years previously). He had no underlying disease. The clinical diagnosis was prurigo nodularis and treatment was started. Oral cyclosporine (200 mg/day) was taken for 1 year, but his symptoms waxed and waned. Treatment was changed to oral alitretinoin (30 mg/day). Within 16 weeks of treatment, the symptoms and skin lesions had improved more than with previous treatment. His treatment with oral alitretinoin continued for 3 years without progression or any side effects.
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.