The different faces of actinomycosis

A 48-year-old woman presented with a 4-week history of progressive, painful skin lesions on trunk and limbs. She reported fatigue, coughing, weight loss and diarrhoea. Her medical history included depression, tobacco smoking, and benzodiazepine and alcohol abuse. On physical examination, three indurated, erythematous, purulent plaques were seen on the lower back, right forearm and left scapula (180 · 60 mm, 70 · 40 mm and 20 · 20 mm in size, respectively). Firm, subcutaneous, purulent nodules were seen on the right hip and upper leg (Fig. 1a,b). The patient was apathetic, with a bloated abdomen, hepatomegaly, and inguinal and supraclavicular lymphadenopathy. The clinical differential diagnosis included lymphoma, inflammatory disease, paraneoplastic syndrome, panniculitis, cutaneous metastasis and lymphangitis carcinomatosa. A skin biopsy was taken. On histopathological examination, a deep chronic, purulent inflammatory infiltrate was seen, consisting of lymphocytes, plasmocytes, neutrophils and histiocytes. Focally Gram-positive radial filamentous organisms were seen, indicative of an infection. Laboratory investigations revealed raised erythrocyte sedimentation rate (56 mm ⁄ h; normal 0–19 mm ⁄ h) and increased levels of C-reactive protein (233 mg ⁄ L; < 10 mg ⁄ L), serum alkaline phosphatase (271 U ⁄ L; 40–140 U ⁄ L), and c-glutamyl transferase (50 U ⁄ L; 0– 40 U ⁄ L). Blood cell counts identified leucocytosis (21.7 · 10 ⁄ L; 3.5–10.0 · 10 ⁄ L), thrombocytosis (815 · 10 ⁄ L; 130–350 · 10 ⁄ L) and normocytic CP D