How is pathophysiology of type I HS?

The “classic” allergies are Type I HS reactions. ➢ Type I (Anaphylactic, Atopic or Immediate) HS can be caused by the body’s response to a foreign substance. ➢ It involves immunoglobulin E (IgE) mediated release of antibodies against a soluble antigen Divided into 3 phases; Phase 1 (Sensitisation), Phase 2 (Activation), Phase 3 (Effector) ➢ The allergens that result in a type I HS may be harmless (i.e., pollen, mites, or foods, drugs, etc.) or more hazardous such as insect venoms ➢ Regardless of the allergen, the first exposure activates a primary IgE antibody response that sensitizes an individual to type I HS reaction upon subsequent exposure