A drug is supposed to cure or at least alleviate our complaints. But medicines can also cause adverse effects. Among the rare but potentially dangerous side effects are drug allergies. In most cases, this results in skin changes in the form of an itchy rash (drug exanthema). However, all other symptoms of an allergy can also occur, from rhinitis to asthma attacks to a life-threatening allergic shock. Anyone who observes such symptoms in themselves after taking a medication should definitely consult a doctor.
Drug allergy in children
Three-year-old Phillip, for example, presented to the emergency department with a severely itchy rash all over his body. The cause was an antibiotic he had taken for three days to treat a febrile middle ear infection. The emergency physician prescribed a new antibiotic and an antipruritic juice (antihistamine) to treat the allergy. Especially in children, it can be difficult to distinguish a drug exanthema from a measles or other viral exanthema. Unclear skin rashes should therefore always be clarified by a specialist, says pediatrician and allergist Dr. Wolfgang Rebien, president of the Medical Association of German Allergists (ÄDA).
Drug allergy – what to do?
If a drug allergy is suspected, allergy testing should be performed by a physician specializing in allergies no earlier than two weeks after the symptoms have subsided, but preferably within the next six months. In some cases, it is possible to obtain indications of the triggering substance with the help of various skin and blood tests. However, certainty is only offered by relatively complex and not entirely harmless examinations in which the patient takes the medication again under medical supervision, reports the Göttingen allergist and dermatologist Professor Dr. Thomas Fuchs. He criticizes that for Germany also from official side no data are available over it, how high the risk for life-threatening running medicament allergies is. There is an urgent need for action here, Fuchs said.
Causes of drug allergy
Relatively often, drug allergies are triggered by antibiotics, epilepsy medications, and painkillers. Gentle natural remedies such as echinacea or chamomile can also cause allergies. Occasionally, allergological diagnostics reveal that the affected person is allergic not to the active ingredient of the drug, but to a so-called auxiliary substance or additive. This may be a colorant, flavoring or preservative. The alleged penicillin allergy may therefore not be triggered by the penicillin at all, but by a dye in the tablet, for example. In this case, allergy diagnostics are of great importance, because the affected person can then very well take penicillin. It just has to be the tablet from another manufacturer that does not contain this dye, Fuchs explains.
Carry allergy passport
It is therefore very important in the case of drug allergies to have the result of the allergy test entered in an allergy passport and to always present it when visiting a doctor. Then any doctor will be able to pick out an optimally effective and tolerable drug. The most effective therapy for drug allergy is to consistently avoid the triggering substance. Sufferers should only take new medications after consulting their doctor. People who have already had an allergic reaction to a drug must also be careful with all other medications. They have a ten times higher risk of developing further drug allergies.
Aspirin can make asthmatics breathless
Not in every case, however, is a true allergic reaction behind the symptoms of a drug allergy. It may also be a so-called pseudoallergy. Unlike an allergic reaction, which usually occurs several days after the first dose of medication, symptoms such as a skin rash, rhinitis, or shortness of breath can occur here as soon as the first dose is taken. An example of a pseudoallergy is bronchial asthma triggered by the painkiller and rheumatism drug acetylsalicylic acid (ASA). In the normal population, the risk of this is less than one percent. In contrast, about one in five adult asthmatics reacts to the intake of ASA with an asthma attack.
