Invasive fungal infections: A diagnostic challenge

Abstract

Introduction: Overall incidence of invasive fungal infections in solid organ transplant recipients is low with the more common infections being invasive candidiasis, aspergillosis and cryptococosis. Zygomycosis comprises of only 0.2%-1.2% of infections in renal transplant recipients with current recommendations advising against routine prophylaxis.

Case: The patient was a 60-year-old male with a history of renal transplant 25 years ago on immunosuppressants, chronic transplant glomerulopathy, squamous cell carcinoma post penectomy and bilateral orchiectomy 2 years ago, controlled diabetes and hypertension who presented with pain in the perineal region for 4 days. On exam he was discovered to be afebrile and had a scrotal skin fold with urethral opening from his previous surgery and 2.5 cm induration and tenderness in the left gluteal fold. He was treated with 5 days of Unasyn. A biopsy was taken to rule out recurrence of squamous cell carcinoma and he was discharged home. The patient returned with worsening perineal pain within 3 days. On exam he had progressive induration with erythema, swelling and tenderness in the perineum. An initial white blood cell count of 15.8 increased to 25.8 and blood cultures remained negative. The computed tomography scan showed diffuse edema in the perineum without any evidence of abscesses. Immunosuppression was held and broad spectrum antibiotics were started. His renal failure progressively worsened eventually requiring continuous renal replacement therapy, intensive care transfer and vasopressor support. The biopsy revealed intermingled fibrous tissue with focal necrosis and no evidence of malignant cells. A repeat incision and debridement (I&D) culture showed growth consistent with mucor. He was started on liposomal amphotericin B and taken to the OR for multiple debridements. Unfortunately he progressed to multisystem organ failure and died after transitioning to comfort care.

Conclusions: Invasive fungal infections remain one of the life threatening differentials for cellulitis like skin lesions, especially for patients not responding to antibiotics and those who are immunocompromised. Early cultures and histopathology of lesions should be done for diagnosis and to avoid delays in treatment.