Which presentation is typical of an anaphylactic reaction?

• A. Generalized erythema with hypotension
• B. Localized erythema only
• C. Mild rhinorrhea
• D. Itching limited to injection site

Answer: (A)

Anaphylaxis is a systemic hypersensitivity reaction where mediators released from mast cells and basophils after exposure to an allergen cause widespread effects. The vasodilator and increased vascular permeability effects lead to skin manifestations like generalized flushing or urticaria and, crucially, can cause a sudden drop in blood pressure as the vascular system becomes leaky and dilated. Generalized erythema with hypotension fits this pattern because it reflects the body-wide involvement and cardiovascular compromise that define anaphylaxis.

Local or mild symptoms, such as erythema confined to one area, mild rhinorrhea, or itching at an injection site, do not indicate a systemic, life-threatening reaction.