A 20-year-old woman with no prior shellfish exposure develops acute onset wheezing, diffuse urticaria, and angioedema within 3 minutes of ingesting shrimp. Vital signs show BP 88/52 mmHg, HR 118 bpm, RR 22/min, temp 37.2°C. Serum tryptase is elevated at 12 ng/mL. She denies previous allergic reactions and takes no medications. She improves rapidly after intramuscular epinephrine 0.3 mg. Which immunologic mechanism best explains this acute reaction?
- A)IgE mediated cross linking on mast cells with release of histamineGABARITO
- B)IgG directed against cell surface antigens with complement activation
- C)Autoantibody stimulation of a hormone receptor
- D)T cell mediated tissue injury from sensitized lymphocytes
- E)Immune complex deposition with neutrophilic inflammation
Explicação
This is a classic type I hypersensitivity reaction. Prior sensitization produced allergen specific IgE bound to mast cells, and re exposure triggered cross linking with rapid degranulation and release of histamine and other mediators. Ver explicação completa e trilha adaptativa →