Are you sure that it is a drug allergy?

Abstract

Adverse drug reactions (ADRs) include 2 types, namely types A and B. Type A ADRs include overdose toxicity, commonly observed side effects, indirect effects, and drug-drug interactions based on a drug's inherent pharmacological action. Type B ADRs include intolerance, drug idiosyncrasy, drug hypersensitivity reactions (DHRs) caused by immunological mechanisms and pseudoallergic reactions caused by nonimmune mechanisms. 1) A DHR is a drug-mediated immunological mechanism in sensitized patients and occurs in a narrow sense in combination with drug allergies (DAs). 2) The clinical manifestation of DA is variable; sometimes children already have various diseases when suspected allergic symptoms occur. In children, respiratory and gastrointestinal symptoms, along with skin symptoms, are the most common allergic symptoms, which are like those of the underlying disease for which the drug is administered. Therefore, clinicians may miss some DAs. Moreover, clinicians diagnose DAs according to drug administration history alone without performing a diagnostic evaluation. Drug provocation tests (DPTs) and skin tests were previously performed for suspected DAs in 43 children who were assessed by physicians to have DHRs. Among them, however, DHRs were confirmed only in 3 patients. 3) The DPTs were positive in about 25%-30% of children with suspected DHR. 4,5) These results differed from those suspected clinically and those confirmed by diagnostic evaluation. The diagnosis of DA based on medical history alone is vague and unreliable, leading to overdiagnosis. Limiting the prescriptions of drugs causing suspected DAs without a definite diagnosis restricts the number of alternative drugs, especially in children who have fewer approved options than adults. It is important to accurately diagnose a DA because difficulty selecting appropriate drugs can result in less effective treatment and the need for subsequent treatment, which in turn can increase medical costs. This review of drug allergies in children 6) highlights a wide range of topics, including DA epidemiology, the causative agent, and diagnostic methods. When diagnosing DA, history taking and examination are important to determining suspected diseases and drugs. Furthermore, objective tests such as skin tests, DPTs, and serum tests are performed. To accurately diagnose