Which type of cutaneous drug eruption occurs within minutes to hours after drug administration?

The type of cutaneous drug eruption that occurs within minutes to hours after drug administration is characterized by immediate hypersensitivity reactions. Urticarial reactions (hives) and angioedema involve the sudden appearance of wheals, which are raised, itchy areas on the skin, as well as potential swelling of deeper layers, particularly around the eyes and lips. These reactions stem from the release of histamine and other inflammatory mediators, often in response to exposure to certain medications, such as antibiotics or analgesics.

The rapid onset—typically within minutes to hours—distinguishes urticarial eruptions from other types of drug eruptions that may take longer to develop. Urticaria is associated with immediate type hypersensitivity, which involves preformed antibodies (IgE), leading to quick reactions upon re-exposure to an allergen. This contrasts with other dermatological reactions to drugs that may have delayed onset or require longer exposure before symptoms present. Therefore, recognizing the characteristics of urticarial cutaneous eruptions is crucial for prompt management and the prevention of complications.