Toxoplasmic myositis as a presenting manifestation of idiopathic CD4 lymphocytopenia

Toxoplasma gondii encysts in skeletal muscle. Although only rarely found at muscle biopsy, this parasite has previously been regarded as a possible cause of polymyositis. We report a case of biopsy‐proven toxoplasmic myositis in a non–HIV‐infected patient that led to recognition of idiopathic CD4 lymphocytopenia (ICL), a rare condition typically associated with opportunistic infections. Interestingly, the CD25+ subset that corresponds to the CD4+ regulatory T cells controlling autoimmune processes was lacking. Steroid and antiprotozoal therapy led to recovery. Muscle Nerve 27: 761–765, 2003