An interesting case of primary cutaneous actinomycosis.

Actinomycosis is an infection commonly seen in tropical countries. It is characterized by chronic and progressive suppurative inflammation, typically presenting on the neck, thorax, and abdomen. Primary cutaneous actinomycosis is a rare entity, and the diagnosis requires a high index of clinical suspicion. Anaerobic cultures may be negative despite repeated attempts. Microscopic examination reveals the diagnosis in the majority of cases, and treatment requires administration of parenteral or oral penicillin for at least 6 weeks. We report a case of cutaneous actinomycosis affecting the arm. This patient was treated with phenoxymethylpenicillin.