[Polymyalgia rheumatica with drug eruption--an important differential diagnosis to dermatomyositis].

With regard to certain clinical features, polymyalgia rheumatica (PR) may closely resemble dermatomyositis. In contrast to dermatomyositis, PR usually does not show any cutaneous manifestations, although there might be seen concomitant giant cell arteritis. Furthermore, we do not find muscle enzymes in the serum with PR, and there is no histologic evidence of myositis. In rare cases, however, PR may be associated with cutaneous drug eruption and/or non-specific increase of muscle enzymes, which might cause considerable difficulties regarding the diagnostic differentiation from dermatomyositis.