NEAR-FATAL ANAPHYLACTIC REACTION TO INTRAMUSCULAR DICLOFENAC INJECTION: EARLY RECOGNITION AND EMERGENCY MANAGEMENT

Abstract

Diclofenac is one of the most widely used nonsteroidal anti-inflammatory drugs (NSAIDs) in clinical practice, yet it remains a significant cause of drug-induced hypersensitivity reactions, including life-threatening anaphylaxis. We report the case of a 21-year-old previously healthy male who developed fulminant anaphylactic shock following intramuscular administration of diclofenac for acute abdominal pain. Shortly after injection, he experienced rapidly progressive generalized itching, followed by diffuse erythematous maculopapular rashes and worsening restlessness. Within hours, he deteriorated to a drowsy and poorly responsive state. On arrival to the emergency department, he was hypotensive with non-recordable blood pressure, bradycardic, and had a Glasgow Coma Scale score of 12/15. Systemic examination revealed widespread rash and mild wheeze, with no evidence of alternative causes for shock. Immediate resuscitative measures were initiated, including high-flow oxygen, aggressive intravenous fluid therapy, intramuscular adrenaline administered in repeated doses, antihistamines, corticosteroids, bronchodilator nebulisation, and eventual intravenous adrenaline infusion. Serum tryptase levels were elevated, supporting the diagnosis of anaphylaxis. Over the next 24 hours, the patient responded well to treatment, stabilized hemodynamically, and was transferred to the MICU for continued monitoring. He was subsequently shifted to the ward and discharged in stable condition after counseling on strict lifelong avoidance of diclofenac and related NSAIDs, with advice regarding emergency preparedness and follow-up with an allergy specialist.

This case underscores the unpredictability and severity of diclofenac-induced anaphylaxis, even in individuals without prior drug allergy. It highlights the importance of early recognition, prompt administration of intramuscular adrenaline, and escalation to vasopressor therapy when needed. Comprehensive patient education and proper documentation play vital roles in preventing recurrence. Awareness of NSAID-induced anaphylaxis among clinicians remains essential for improving outcomes in emergency settings.