A 33-year-old man received equine-derived antitoxin following a snakebite. Eight days later, he presents with fever (38.8°C), diffuse arthralgias, urticarial rash, and mild dyspnea. Vital signs show HR 102/min, BP 128/76 mmHg, RR 20/min, SpO2 98% on room air. Urinalysis reveals 2+ proteinuria. He denies previous antitoxin exposure. Which of the following best explains the pathophysiologic mechanism of this reaction?
- A)Preexisting antibodies against donor endothelial antigens
- B)Direct T cell cytotoxicity against skin keratinocytes
- C)IgE mediated mast cell degranulation
- D)Antibody dependent cellular cytotoxicity by natural killer cells
- E)Immune complex deposition with complement activationGABARITO
Explicação
This patient has serum sickness, a classic type III hypersensitivity reaction. Circulating antigen antibody complexes deposit in tissues, activate complement, and cause fever, arthralgias, rash, and glomerular injury days after exposure. Ver explicação completa e trilha adaptativa →