Epidemiology and Risk Factors in Drug Hypersensitivity Reactions

Opinion Statement

Data on adverse drug reactions (ADRs) is abundant, especially regarding prevalence and incidence among hospital-based populations. Most studies, however, do not differentiate between drug hypersensitivity reactions (DHRs) and other kinds of ADR, and in those ones where this information is available, the diagnosis of DHR or drug allergy is mostly based on a suspected clinical history or self-reporting as the majority of patients are not referred for an allergy diagnostic workup. Large studies in drug allergy clinics revealed that only 10 to 20% of the initial DHR suspicions are actually confirmed after investigation. Diagnosis based only on clinical histories largely overestimates drug hypersensitivity, so specific data on DHR is scarce and generally of low quality. Epidemiological data, although limited, can help researchers to identify potential risk factors for DHR. Females seem to be more susceptible than males to ADR and DHRs in adult populations, while the female gender is not a risk factor among children. ADRs have also a higher incidence among young children and among the elderly. The role of atopy as a risk factor for DHR is still debatable; however, recent evidence shows that it can actually be important considering reactions to betalactams and NSAIDs. Comorbidities as infections and underlying chronic diseases are known risk factors both for ADR in general and for DHR. The most recent investigation concentrates on the importance of genetic risk factors, and many gene polymorphisms have been identified with strong associations to particular kind of DHR and/or to reactions to specific drugs. This article will discuss general limitations of the available epidemiological data on DHR and will present an in-depth review of the main identified risk factors for drug reactions with special focus on genetic findings.

http://ift.tt/2r2g5qO