A Brush With the Lake: Recurrent Lower Extremity Cellulitis in a 50-Year-Old Male.

Cellulitis is a leading cause of hospitalization in the United States. While β-hemolytic streptococci and Staphylococcus aureus predominate, patient comorbidities and environmental exposures may shift the spectrum of causative organisms. We report the case of a 50-year-old man with diabetes, prior left-leg deep vein thrombosis, chronic lymphedema, and recurrent cellulitis who presented with progressive lower-extremity erythema and pain following freshwater exposure. He failed multiple outpatient and inpatient empiric regimens and had non-diagnostic cultures. Magnetic resonance imaging demonstrated gastrocnemius myositis. Given characteristic dermatological morphology and exposure history, antipseudomonal therapy was initiated on hospital day four, resulting in rapid improvement. This case highlights the importance of integrating exposure history and attendant skin morphology to guide therapy in culture-indeterminate, refractory cellulitis and support antimicrobial stewardship.