Which of the following is NOT a typical side effect during a Type 1 hypersensitivity reaction?

In a Type 1 hypersensitivity reaction, which is mediated by IgE antibodies, the body reacts to an allergen, leading to the release of histamine and other inflammatory mediators from mast cells and basophils. This reaction is commonly associated with symptoms such as itching, tachycardia, and rhinitis.

Itching is a hallmark symptom, arising from the histamine release that excites nerve endings in the skin. Tachycardia can occur due to the systemic effects of these mediators, as the release of histamine can influence heart rate. Rhinitis is another common manifestation, characterized by symptoms like nasal congestion and sneezing, reflecting the allergic response in the upper respiratory tract.

Hypertension, however, is not a typical side effect of a Type 1 hypersensitivity reaction. In fact, rather than hypertension, anaphylaxis – a severe form of Type 1 hypersensitivity – often leads to hypotension due to widespread vasodilation caused by mediators like histamine. Therefore, while itching, tachycardia, and rhinitis align with typical reactions in an allergic response, hypertension does not fit this pattern, making it the correct answer for the question.