Latex allergy — formative SAQs

SAQ 1 — Intraoperative latex anaphylaxis (10 marks)

A five-year-old with myelomeningocele and a ventriculoperitoneal shunt develops generalised urticaria, wheeze and hypotension 40 minutes into an elective orthopaedic procedure. No new drug has been administered since induction 40 minutes earlier. ^[12]

Questions

1. What is the most likely diagnosis, and which feature in the history distinguishes it from drug-triggered anaphylaxis? (3 marks) ^[12]

2. Outline the immediate resuscitation and the investigation pathway after the event. (4 marks) ^[15]

3. Describe the long-term management and the institutional precautions for this child. (3 marks) ^{[5] [11]}

Model answer

Diagnosis and distinguishing feature (3). This is intraoperative anaphylaxis to natural rubber latex, the classic scenario for a child with spina bifida (historically 30 to 70 per cent sensitised). The distinguishing feature is the delayed onset — 30 to 60 minutes into surgery, reflecting mucosal absorption of latex protein via the peritoneum or surgical wound. Drug-triggered anaphylaxis (neuromuscular blockers, antibiotics, induction agents) fires within minutes of administration at induction. The spina bifida history and the delayed timing make latex the leading diagnosis. ^[12]

Resuscitation and investigation (4). This is anaphylaxis — a clinical diagnosis. Give IM adrenaline into the anterolateral thigh first (roughly 0.01 mg/kg of 1:1000, or a weight-banded autoinjector: 0.15 mg at her weight); call for help; lie flat with legs elevated if shocked; high-flow oxygen and IV fluids for hypotension; bronchodilator adjunctive for wheeze. Repeat adrenaline at five minutes if no response. Remove all latex from the environment and eliminate powdered latex gloves from the entire operating suite. After the event, follow the perioperative anaphylaxis pathway: serial serum tryptase at 1 to 2 hours, 4 hours, and baseline at follow-up; refer to an allergy specialist; and document the latex-safe requirement in the anaesthetic and surgical notes. ^[15]

Long-term management (3). Strict latex avoidance for life: latex-free gloves, catheters, and devices; avoid balloons, rubber bands, and latex-containing household items. Latex-safe surgery protocol for all future procedures: first case of the day, latex-free operating room, removal of all powdered latex gloves from the suite, and latex-free equipment. Provide a written anaphylaxis action plan (ASCIA/BSACI/FARE), a weight-banded adrenaline autoinjector, and medical alert identification. Notify the school, dentist, and all treating clinicians. Confirm the diagnosis with skin-prick testing, serum latex-specific IgE, and component-resolved diagnostics (Hev b components). Counsel on latex-fruit syndrome foods (banana, kiwi, avocado, chestnut). ^{[5] [11]}