AREA 51: UNUSUAL BUT TRUE CASES

Antibiotic-Resistant Suppurative/
Granulomatous Dermatitis
A 79-year-old woman presented to her primary care physician in May 2005 with a "spider bite" that began as two lesions on her forearm near her elbow, sustained three weeks previously in Hawaii. After 10 days on Keflex, the raised, erythematous to purple skin changes were still evident, and seven additional lesions had appeared distally. The patient was referred to a dermatologist on May 17, who described red to blue confluent plaques arrayed in a linear, sporotrichoid fashion along the lateral forearm distal to the initial lesions at the far right in Fig. 1.

Fig. 1

He obtained two 4 mm punch biopsies, one in formalin and one in broth for culture, and started Lamisil 250mg/d x 12d for this "painful, edematous cellulitis". Autolyzing neutrophils were the central element in this inflammation, surrounded by histiocytes and histiocyctic giant cells with an outer fringe of lymphocytres (Fig. 2). While this suppurative/granulomatous dermatitis was deemed most likely an infectious disease process, no fungal or mycobacterial agents could be found in initial PAS, GMS, Fite and acid-fast stains. New distal forearm lesions appeared while on Lamisil. On May 26, newer nodules from this "painful edematous cellulities" were biopsied, again with provision for microbiological culture. Cipro 500mg bid x 10d was prescribed. By June 8, the patient reported no improvement, in fact the older nodules were returning, so she was switched to Minocycline 100 mg/d x 7 d, without beneficial effect.

Fig. 2

This progressive process is most likely: ______________________.

CLICK HERE FOR ANSWER.