Skin Allergies

Drugs can cause allergic reactions. They most commonly manifest as a red itchy rash on the body. Other symptoms that may occur in the setting of an allergic drug reaction include:

• Hives
• Angioedema( swelling of the eyes or mouth or face)
• Blisters on the skin
• Broken skin( erosions)
• Sun sensitivity
• Few discrete red circular spots on the skin ( otherwise known as ”fixed drug eruption”)

Although most allergic drug reactions are not serious, and can be simply treated by stopping the drug and taking some symptomatic treatment, there are a few allergic drug reactions that are potentially very serious and may be life-threatening. One form of severe allergic drug reaction is called Steven Johnsons syndrome or Toxic epidermal necrolysis. In this condition, one develops painful blisters and broken skin affecting large areas of the body. The appearance of the skin is often liken to the effect of suffering from burns. Often, the mouth is ulcerated causing severe pain and difficulty in eating.

Another form of severe allergic drug reaction is called anaphylaxis. Anaphylaxis occurs within minutes to hours after taking the drug. In this condition, the person often develops widespread hives, swelling of the face/eyes/ lips/tongue, together with breathing difficulty and giddiness. Other symptoms include difficulty swallowing, feeling of a lump in the throat, stomach cramps, feeling cold and clammy. If emergency medical attention is not sought, anaphylaxis can be life-threatening.

Drug allergy testing is usually not required if the culprit drug is obvious. However, allergy testing may be necessary if there is uncertainty if the skin reaction was indeed caused by a drug allergy, or if the person was multiple drugs at the time of the reaction and it is unclear which drug was the cause of the allergy. There are different forms of drug allergy testing including blood tests, skin tests and drug challenge testing.