How soon after exposure to an allergen can symptoms of an allergic reaction onset?

Symptoms of an allergic reaction can often onset within minutes to two hours after exposure to an allergen. This timing is particularly relevant for immediate hypersensitivity reactions, which are mediated by immunoglobulin E (IgE) and typically lead to quick responses, such as hives, swelling, or respiratory issues.

Responses classified under this timeframe reflect the body's quick immunological response to allergens like pollen, food, or insect venom. In many cases, individuals may experience symptoms almost immediately, making it crucial for those with known allergies to be aware of their triggers and prepared to manage their reactions.

This option accurately represents the common timeline for reactions to occur after allergen exposure, emphasizing the need for prompt recognition and treatment of allergic responses.