Cutaneous reactions to thalidomide therapy are reported infrequently. We report two new cases. Both patients suffered from chronic renal insufficiency and were on thalidomide therapy because of prurigo nodularis. The cutaneous reaction consisted of a severe erythematous rash progressing to erythroderma, associated with peripheral eosinophilia. In both cases rapid resolution occurred after withdrawal of thalidomide. We emphasize the possibility of a severe cutaneous hypersensitivity reaction due to thalidomide and speculate about the role played by the renal insufficiency present in both cases.