Treatment of prurigo nodularis with thalidomide: a case report and review of the literature

A 37‐year‐old man was first seen on 20 March 1997 for a 5‐year history of widespread, persistent, and intensely pruritic skin lesions on all the extremities. Two years following the appearance of prurigo nodularis (PN), the patient developed a major depressive disorder for which he was given antidepressant agents (amitriptyline and clonazepam) by the psychiatrist. His past history also revealed hepatitis B virus infection. Examination revealed numerous, excoriated, erythematous papules and nodules on all extremities of variable size (ranging from 1 to 3 cm), accompanied by secondary pigmentary changes and scars ( Fig. 1). Investigations revealed normal complete blood count (CBC), urea, creatinine, and liver enzymes. Hepatitis B surface antigen was positive. 1Lesions prior to treatment. Numerous nodules at different locations in the upper and lower extremities The patient was treated with several modalities, including antihistamines and topical and intralesional corticosteroids, but with no significant improvement. His depressive symptoms failed to respond and he continued to deteriorate such that he started to exhibit suicidal gestures. On assumption that the continuous itching caused by PN was a major factor in his depression and with the risk of suicide, the decision was made to start thalidomide. On 20 July 1997, thalidomide was started at a dose of 100 mg twice a day after normal baseline work‐up, which included a nerve conduction study, CBC, urea, creatinine, and liver function tests. Because of the history of hepatitis B infection, ultrasound of the liver was performed and was reported to be normal. All topical corticosteroids and antihistamines were discontinued and the patient was allowed to use emollient. On 10 August 1997, pruritus had decreased, but with no change in the skin lesions. The patient tolerated thalidomide, and the dose was increased to 100 mg every morning and 200 mg every evening. On 22 March 1998, there was no pruritus, and skin examination revealed the clearance of most of the lesions and flattening of others ( Figs 2 and 3). Central nervous system examination revealed mild sensory loss over both ankles. These changes were seen after a cumulative dose of 79 g. The dose was reduced to 100 mg orally twice a day. A nerve conduction study in May 1998 of three nerves (medial, perennial and surreal) confirmed the clinical findings of mild sensory neuropathy. Because of his very extensive and still active disease, the failure of previous therapeutic modalities, and history of suicidal gestures, full discussion concerning thalidomide side‐effects was carried out with the patient and the neurologist, and the decision was made to taper his thalidomide gradually and to monitor for a worsening of neuropathy. 2Lesions after 4.5 months of treatment. Flattening of the nodules can be seen3Lesions after 8 months of treatment. The disappearance of most lesions and flattening of others can be seen with very obvious secondary hypo‐ and hyperpigmentation and scars During the last 3 months prior to the discontinuation of thalidomide (December 1998 to February 1999), the patient was on a maintenance dose of 50 mg every other day, reaching a cumulative dose of 111 g. A nerve conduction study at the end of treatment (February 1999), compared to the previous study in May 1998, showed a continuous decrease in amplitude of the sensory nerve action potential with unchanged sensory conduction velocity. His hemogram and blood chemistry remained within the normal range during treatment. Four months after the discontinuation of thalidomide, the patient is still in remission with residual hypo‐ and hyperpigmentation and a few scars, and his peripheral neuropathy has improved significantly.