Necrotizing external otitis: diagnostic clues in the emergency department

Area of Science:

• Otolaryngology
• Emergency Medicine
• Diagnostic Accuracy

Background:

• Necrotizing external otitis (NEO) diagnosis requires a high index of suspicion.
• Accurate diagnostic parameters in the Emergency Department (ED) are crucial for timely intervention.

Observation:

• A retrospective study evaluated 24 patients presenting with symptoms suggestive of NEO.
• Key parameters assessed included otoscopy, physical examination, CT, and laboratory results (ESR, CRP).
• Nuclear imaging served as the gold standard for diagnosis.

Findings:

• Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) showed significant diagnostic accuracy for NEO (AUC 0.92 and 0.8, respectively).
• Elevated ESR (>26 mm/h) and CRP (>10 mg/L) yielded high positive likelihood ratios, strongly suggesting NEO.
• Clinical and radiological findings were less accurate compared to ESR and CRP.

Implications:

• ESR and CRP are valuable, accessible biomarkers for suspecting NEO in the ED.
• Normal ESR and CRP levels can help rule out NEO, prompting consideration of alternative diagnoses.
• Integrating ESR and CRP into ED protocols can improve NEO diagnostic efficiency.