{"operator":"Indus Intellect LLC","notice":"Every case is a Draft - not clinically validated, pending Dr. Carlo Raj clinical sign-off. Educational simulation content only; not medical advice. No doses are published. No CME.","access":"teaser","case":{"id":"hypersens_anaphylaxis_01","title":"Swelling and wheeze after peanut — anaphylaxis","draft_flag":"Draft - pending Dr. Carlo Raj clinical sign-off","validated":false,"objectives":["Diagnose anaphylaxis clinically without waiting for tests","Give IM epinephrine first, reassess at 5 minutes and repeat if ABC problems persist","Explain type I hypersensitivity"],"foundation_concept":"Allergen cross-links IgE bound to mast cells and basophils, releasing histamine and other mediators that cause vasodilation, leak and bronchospasm (type I hypersensitivity)","presentation":{"age_sex":"20s M","chief_complaint":"Lip swelling, itchy rash and wheeze minutes after eating","history_clue":"Known peanut allergy; ate a dish containing peanut minutes earlier","exam_localising":"Generalised urticaria, lip angioedema, stridor and wheeze, hypotension. The reaction localises to systemic mast-cell degranulation"},"vitals":{},"history_items":["Asks about the trigger and timing"],"exam_items":["Assesses airway, breathing and circulation","Reassesses airway, breathing and circulation 5 minutes after epinephrine"],"orders":["Serum tryptase"],"results":{"tryptase":"Serum tryptase drawn later supports the diagnosis (does not delay treatment)"},"interventions":["IM epinephrine into the anterolateral thigh immediately","Keeps the hypotensive patient flat with legs raised where tolerated; supported semi-recumbent only for breathing difficulty; no sudden sitting up, standing or walking","High-flow oxygen and IV fluid bolus","Repeats IM epinephrine after 5 minutes because airway, breathing or circulation problems persist","Escalates to critical care for refractory anaphylaxis","Antihistamine as an adjunct","Risk-based observation period, then discharge with an epinephrine auto-injector and allergy referral"],"differential":["Anaphylaxis (working diagnosis)","Asthma exacerbation (no urticaria or hypotension)","Hereditary angioedema (no urticaria, bradykinin-mediated)"],"critical_actions":["IM epinephrine given","Airway assessed","ABC reassessed after the first dose","Repeat IM epinephrine after reassessment shows persistent ABC problems","Discharge only after symptoms resolve"],"harmful_actions":["Antihistamine given before epinephrine","Discharge planned before symptoms resolve","Hypotensive patient sat upright or walked (risk of collapse)"],"mechanism":{"prompt":"Why is epinephrine first and antihistamine only an adjunct?","steps":["Mast-cell mediators cause vasodilation, capillary leak and bronchospasm","Epinephrine reverses all three via alpha-1 and beta-2 receptors","Antihistamines block only one mediator and act too slowly for the airway or shock"],"question":{"text":"Which immunoglobulin, bound to mast cells, triggers anaphylaxis?","options":[{"id":"OPT1","text":"IgE"},{"id":"OPT2","text":"IgG"},{"id":"OPT3","text":"IgM"},{"id":"OPT4","text":"IgA"}],"answer":"OPT1"}},"disposition":"Observe for a risk-based period after resolution; escalate to critical care if refractory; discharge only once resolved, with an auto-injector and allergy referral","notes":[]}}