Recurrent Lower Extremity Pseudocellulitis in a Liver Transplant Recipient: Suspected Tacrolimus-Associated Drug Eruption.

Cutaneous drug eruptions can closely mimic cellulitis, creating a diagnostic challenge in transplant recipients receiving multiple potentially contributory medications. We report recurrent lower-extremity pseudocellulitis in a 55-year-old liver transplant recipient whose clinical course raised suspicion for a tacrolimus-associated drug eruption. Over 11 months, she was hospitalized 10 times and received multiple therapeutic and prophylactic antimicrobial regimens without sustained improvement. Repeated microbiologic studies, including bacterial, fungal, and acid-fast bacillus tissue cultures, were negative. Dermatologic evaluation and skin biopsy demonstrated a superficial and deep perivascular, perieccrine, and focally interstitial inflammatory infiltrate without evidence of infection or vasculitis. The relapsing course, negative microbiologic evaluation, and nonspecific inflammatory biopsy findings favored a noninfectious process. Tacrolimus was considered one possible contributor based on the reported onset after transplantation and recurrence during continued exposure, although uncertain latency and concomitant antimicrobial exposure limited causal attribution.