[Papular drug eruption along the lines of Blaschko caused by lenalidomide].

Cutaneous drug reactions can take many forms. In rare cases these reactions can occur along the lines of Blaschko. A 60-year-old patient received lenalidomide in 3-weeks-cycles for the treatment of a plasmocytoma. After four months of treatment, red papules appeared on the extremities and the trunk following the lines of Blaschko. The lesions nearly disappeared during drug-free intervals and appeared with renewed intensity after restart of a therapy cycle.