Selective anaphylaxis to paracetamol in a child.

Area of Science:

• Clinical Immunology
• Pediatric Allergy
• Drug Hypersensitivity

Background:

• Paracetamol (acetaminophen) is a common analgesic and antipyretic.
• Anaphylaxis to paracetamol is exceptionally rare, particularly in pediatric populations.
• Limited documented cases exist, necessitating further awareness.

Observation:

• A 15-year-old male experienced four episodes of anaphylaxis post-paracetamol administration since age 8.
• The most severe episode involved glottis edema, respiratory distress, hypotension, urticaria, and facial edema after IV paracetamol.
• Ibuprofen was consistently tolerated; meloxicam challenge was negative.

Findings:

• Despite recurrent severe anaphylaxis, skin prick tests, intradermal tests, serum-specific IgE, and CAST to paracetamol were negative.
• This suggests non-IgE mediated hypersensitivity or other diagnostic challenges for paracetamol allergy.
• The patient tolerated other non-steroidal anti-inflammatory drugs (NSAIDs).

Implications:

• This case underscores the potential for severe anaphylaxis to paracetamol, even in children.
• Healthcare professionals should maintain a high index of suspicion for paracetamol-induced anaphylaxis, despite negative allergy tests.
• Further research into diagnostic methods for paracetamol hypersensitivity is warranted.