Necrotizing Fasciitis Mimicking Interstitial Cystitis: An Atypical Clinical Presentation.

Necrotizing fasciitis is a severe, life-threatening disease with a nonspecific clinical presentation, making it a challenging diagnosis. Early treatment with broad-spectrum antibiotics and surgical debridement is crucial to prevent rapid disease progression and poor outcomes. Given its high mortality rate and ambiguous presentation, maintaining a high index of suspicion for necrotizing fasciitis is essential. In this case, a 60-year-old woman presented to her gynecologist with urinary tract infection symptoms of frequency, hematuria, and suprapubic pain, with a year-long history of night sweats, hematuria, dysuria, and incomplete voiding. Although initially treated with outpatient antibiotics, she returned to the emergency department one day later with severe lower abdominal pain, overlying erythema, and a high fever. Abdominal imaging revealed extensive cellulitis. Upon the development of rapidly expanding erythema and crepitus, there was concern for necrotizing fasciitis. The patient received immediate treatment with broad-spectrum antibiotics and underwent urgent surgical debridement. While she showed clinical improvement in the following days, laboratory studies revealed profound hypercalcemia, anemia, and persistent leukocytosis. Additional testing ultimately led to the diagnosis of advanced bladder cancer. This case underscores the importance of prompt recognition and treatment of necrotizing fasciitis. It also highlights the influence of confirmation and availability biases, which can lead to overlooking symptoms that may indicate more serious underlying conditions. As medical professionals, it is crucial to remain vigilant and not disregard seemingly insignificant symptoms, as they could be indicative of life-threatening diagnoses.