What are the causes of drug hypersensitivity?

Certain medications cause fever, rash, and inflammation of internal organs. When such symptoms occur as a pattern, the person has contracted drug hypersensitivity syndrome. If left unchecked the syndrome can prove fatal. Studies have shown that the incidence of 10% mortality is prevalent.

As early as 1959 the syndrome was under study. The naming of the syndrome happened only in 1996. The nomenclature also includes the acronym DRESS for Drug reaction with eosinophilia and systemic symptoms; Different patients have varying reactions to a single drug. One of the reactions occurs 7 to 10 days after the drug has entered the body. The symptoms may include fever and rash. Some patients may exhibit edema and gastrointestinal symptoms which may last for 7 to 14 days.

DRESS is known to occur 12 weeks after the drug has entered the system. Patients have increased counts of eosinophilia characterized by facial swelling, edema, and hepatitis among others. Some patients suffer from respiratory distress with wheezing causing deterioration in breathing.

Diagnosing the condition is via patient’s reports after starting the drug and by skin testing. The principal diagnosis is to differentiate the condition from toxic drug symptom. Skin testing requires careful analysis as a misdiagnosis can result in ananaphylactic reaction.

Treatment is discontinuation of the drug and supported by antihistamines as well as acorticosteroid. Desensitization is also a recommended line of treatment if the drug is the only available choice. This treatment again requires careful consideration.