Anaphylaxis & Anaphylactic Shock

Also known as Anaphylaxis · Anaphylactic shock · Anaphylactoid reaction · IM adrenaline · Tryptase · EpiPen

Anaphylaxis — the severe, life-threatening systemic hypersensitivity reaction. The rapid onset (the skin/mucosal + the respiratory + the cardiovascular + the GI). The IgE-mediated (most) or the non-IgE (the anaphylactoid). The IM adrenaline 0.5 mg FIRST; the 100% O2; the IV fluid; the positioning. The IV adrenaline infusion for the refractory. The tryptase for the diagnosis. The observation 6-24 h (the biphasic).

high32 referencesUpdated 17 Aug 202626 min readSource-verified · Sept 2026

Checked against its sources on 2 Sept 2026

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8 MCQs

Overview & definition

Anaphylaxis is the one emergency where seconds decide survival — IM adrenaline 0.5 mg goes in before you finish the assessment. It is the most severe clinical presentation of an acute systemic allergic reaction — rapid in onset and involving the skin or mucosa plus the airway, breathing, circulation, or gut at once. Death is rare but real: risk climbs with asthma, peanut or tree-nut allergy, and delayed or inadequate treatment — and intramuscular adrenaline remains the first-line treatment in every guideline.^[5]^[1]^[25]

References32Show

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