Overview
SJS and TEN are among the most severe drug eruptions. Characteristically, they affect the skin and mucous membranes.
Causes
Drugs which can cause SJS/TEN include anticonvulsant medications, sulphur antibiotics or various other antibiotics and NSAIDs.
SJS and TEN are often preceded by a prodromal phase of fever, cough and malaise. This is followed by an acute red rash that progresses to widespread skin detachment, as cell death causes the superficial layer of skin (epidermis) to separate from the deeper layer (dermis). Red and sore eyes, as well as ulcers affecting the mucous membranes of the oral cavity, lips and genitalia are common features. SJS and TEN typically occur 7 to 21 days after initiation of the drug. They are associated with significant mortality and morbidity.
Prevention
What is a drug provocation test?
A drug provocation test is the controlled administration of a drug to diagnose an immune-mediated and non–immune-mediated drug reaction. It is usually done under medical supervision. Drug provocation test has the potential risk of inducing a more severe and uncontrollable relapse of the original reaction. It is therefore a test which should be reserved for specific situations and when the benefits outweigh the risks.
Detection & Treatment
Evaluating drug allergies/ cutaneous adverse drug reactions can be challenging. An accurate, detailed history and clinical examination will help to establish the type of CADR and to identify the culprit drug. Blood tests, skin biopsies and skin tests (eg. Skin prick tests, intradermal tests and patch tests) are sometimes needed in the evaluation, but the usefulness of these tests is dependent on the type of the reaction and the drugs involved.
Not all cases of drug allergies/ cutaneous adverse drug reactions require specific drug allergy testing and not every medication or type of CADR has a blood test or skin test to help in the diagnosis.
Early diagnosis with prompt withdrawal of the culprit drug can lead to better outcomes. Patients should be hospitalized for close monitoring, supportive care and specific treatment.
Care Management
After a drug allergy or hypersensitivity has been diagnosed, what should you do?
It is important to remember the drug(s) which you are allergic to and always inform your doctors about it. A wallet-size card stating the name of the drug and the reaction you had would be most useful in case of emergency. Avoidance of drugs which are you are allergic to will prevent unnecessary morbidity or mortality.
Drug allergies are captured on the electronic medical records that link many hospitals and clinics.
Specialties & Services
