What is the term for subcutaneous swelling due to an allergic reaction to food or drugs?

Angioedema is the term used to describe subcutaneous swelling that often results from an allergic reaction to food, medications, or other allergens. This swelling typically occurs in areas of the body like the face, lips, throat, and sometimes the extremities. The underlying cause of angioedema involves an increase in the permeability of blood vessels, leading to fluid leakage into the surrounding tissue, which manifests as swelling.

Unlike other conditions such as rosacea, which involves persistent redness and visible blood vessels on the face, or urticaria, commonly known as hives, which consists of raised, itchy welts on the skin's surface without deep swelling, angioedema specifically refers to deeper tissue swelling. Psoriasis, on the other hand, is a chronic autoimmune condition characterized by red, scaly patches on the skin, and does not involve the acute swelling associated with angioedema. Therefore, angioedema is distinct in its presentation and causes, which primarily relate to allergic responses.