It is important to understand that particularly type I and type IV hypersensitivity reactions can both set off a systemic inflammatory response.
Type I by histamine (anaphylaxis)
Type IV by TNF and IFN-y (delayed hypersensitivity)
and because of the sulfa allergy I threw in for differential anaphylactoid reaction.
(Recall that the medical suffix "oid" means looks like but isn't.)
By understading the difference in chemical mediators and actions, you can use physical signs and symptoms to help differentiate between the type IV and the anaphylactoid reaction.
While type IV is often associated with a PPD test, contact dermatitis, and poison ivy, oak, and sumac, it also has implications is such things as severe asthma refractory to treatment.
The more you understand pathophys, the better you physical exam and prognosis will be.
Type I by histamine (anaphylaxis)
Type IV by TNF and IFN-y (delayed hypersensitivity)
and because of the sulfa allergy I threw in for differential anaphylactoid reaction.
(Recall that the medical suffix "oid" means looks like but isn't.)
By understading the difference in chemical mediators and actions, you can use physical signs and symptoms to help differentiate between the type IV and the anaphylactoid reaction.
While type IV is often associated with a PPD test, contact dermatitis, and poison ivy, oak, and sumac, it also has implications is such things as severe asthma refractory to treatment.
The more you understand pathophys, the better you physical exam and prognosis will be.
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