A case of hidradenitis suppurativa complicated by necrotizing soft tissue infection

Diagnosing necrotizing soft tissue infection (NSTI) in the emergency department remains challenging and is primarily a clinical diagnosis despite the availability of decision tools and advanced imaging. In patients with Hidradenitis Suppurativa (HS), baseline skin changes, prior surgical interventions and disrupted tissue planes may obscure early findings, while presentations can mimic less severe conditions such as cellulitis, abscess, or an HS flare. We present the case of a 28-year-old man with HS on adalimumab who presented with left axillary pain and swelling at a prior HS site. He was tachycardic but afebrile with localized erythema on initial examination. On repeat evaluation 50  minutes later, the erythema had rapidly extended along the lateral thoracoabdominal wall, raising concern for NSTI. The patient underwent emergent operative exploration, which revealed copious purulent fluid with disruption of fascial plans and nonviable tissue, consistent with NSTI. His postoperative course was prolonged, requiring surgical intensive care, and he was discharged to subacute rehabilitation on hospital day 25. NSTI in patients with HS may present with subtle or nonspecific findings, and underlying disease-related changes may obscure early diagnosis. These cases require a high index of suspicion, frequent reassessment, and early surgical intervention to optimize outcomes.