Atopy and anaphylaxis are hypersensitivities in the category?
Atopy is a type I hypersensitivity reaction that involves IgE antibodies, leading to immediate allergic responses like hay fever and asthma. Anaphylaxis is a severe, life-threatening allergic reaction that involves a systemic release of histamine and other mediators, causing symptoms such as difficulty breathing and low blood pressure. Both atopy and anaphylaxis are mediated by an exaggerated immune response to normally harmless substances.