Primary immunodeficiencies (PIDs) encompass more than 250 different pathological conditions. X-linked agammaglobulinemia (XLA) has been occasionally associated with cutaneous and muscular manifestations resembling dermatomyositis, often termed dermatomyositis-like syndrome (DLS). This syndrome has been associated with cutaneous, muscular and central nervous system manifestations, accompanying a persistent infection by an Echovirus. According to sixteen previously reported cases, this syndrome has a poor prognosis. We report the case of a 27-years old male, with XLA and DLS, successfully treated with 6 cycles of human immunoglobulin and methotrexate. Clinical symptoms improved dramatically with a complete resolution of the musculoskeletal manifestations. Despite this clinical response, prognosis should remain reserved. The evolution of this syndrome remains unpredictable and therapeutic options are limited. To the best of our knowledge, there are only a few reports of similar cases which have survived so many months after the diagnosis.