(A&E) (Peri-Op & Anaesthesia) (GP)

Overview

• Acute, life-threatening, type 1 hypersensitivity reaction due to IgE-mediated mast cell activation
• Aetiology → food allergies, insect stings, drug reactions (eg. penicillin, latex)
• Degranulation of Mast Cells → Massive Histamine Release → Systemic Vasodilation → Increased Capillary Leakage → Anaphylactic Shock
• Risk Factor ⇒ hx of atopy

Making Diagnosis

Clinical Features:

• Acute Onset
• Airway Swelling (Angio-Oedema)
• Stridor, Dyspnoea, Wheezing, Respiratory Arrest
• Pale, Clammy skin, Hypotension, Tachycardia, Confusion
• Urticaria, Erythema, Pruritus

Investigations:

• Mast-Cell Tryptase → may remain elevated for up to 12hrs after acute episode