Primary cutaneous actinomycosis: a rare soft tissue infection.

Actinomycosis caused by Actinomyces spp. is a chronic and suppurative infection caused by an endogenous gram positive bacterium. The unusual sites of infection are the head and neck, thorax and abdomen and are almost always endogenous in origin. Primary cutaneous actinomycosis is very rare and is usually associated with external trauma and local ischemia. We report a case of a primary cutaneous actinomycosis of the thigh in a 30-year-old man. The patient acquired the infection through an injection wound which progressed to multiple discharging sinuses. Clinical material from the wound demonstrated the presence of Actinomyces in smears and cultures. The patient was diagnosed and successfully treated with surgical resection and combined antibiotic therapy.