Drug (Medication) Allergy

Allergic reactions to drugs (medications) are called ‘immediate’ when they occur within one to six hours after taking a medication, and ‘non-immediate’ when the reaction occurs more than 24 hours after taking a medication. Severe cutaneous adverse reactions (SCAR) are non-immediate rashes due to drugs that are associated with fever, flu-like and other systemic symptoms. These can be life-threatening, and require urgent specialist care. Anaphylaxis is the most severe type of allergic reaction to drugs and requires immediate treatment with adrenaline (epinephrine), Sometimes rashes are mistaken as an allergic reaction to a drug so it is important to confirm whether it is an allergy, or a rash that may be due to infection.