Amoxicillin is a standard antibiotic often used in primary care settings. It consists of an aminopenicillin, with an extra amino group added to the penicillin, which fights antibiotic resistance (Akhavan et. al., 2020). It may cause difficulties in patients with hypersensitive reactions. The types of reactions determine the severity of the symptoms. Type-I and type-IV are the most important to remember as one can be more dangerous than the other. A type-I reaction activates a histamine release which in turn causes a pruritic rash in mild cases and systemic issues, such as anaphylaxis, in serious circumstances.
While in general it is recommended that skin testing be done prior to drug provocation test in the evaluation of amoxicillin allergy, there is increasing evidence that drug provocation testing could be done in lower risk children without skin testing prior. It is estimated that while 10% or children have an amoxicillin allergy, most patients are able to tolerate the antibiotic after being evaluated (Abrams & Moshe, 2019). Testing remains necessary as allergic reactions to amoxicillin often suggest negative effects on health, but the methods remain debatable.
There have been multiple studies that suggest that lower-risk patients can take drug provocation tests without prior skin testing. In a study, pediatric patients with histories of allergic reactions to amoxicillin were tested with the antibiotic. However, the study continued a 5-day administration to those patients that did not present immediate allergic reactions (Labrosse et.al., 2018). A similar study focused on testing children with history of instant reactions, including anaphylaxis, with skin prick test and additional oral graded exams (Faitelson et.al., 2018). The skin tests did not help the diagnosis of amoxicillin allergies but the history of drug allergies, asthma, and reaction during older age sufficed as predictive elements for actual reactions to the antibiotic.
In a recent study, allergists observed that patients, especially children, with amoxicillin-associated allergic reactions became non-allergic when rechallenged with the antibiotic. They showed symptoms of urticaria, maculopapular exanthem (MPE), and serum sickness-like reaction (SSLR) (Labrosse et. al., 2019). During the re-exposure, there were more patients presenting signs of SSLR than expected. The study provides a space to phenotype patients presenting allergies in relation to amoxicillin during primary care.
References
Abrams, E. M. & Moshe, B. S. (2019). Should testing be initiated prior to amoxicillin challenge in children? Clinical and Experimental Allergy, 49(8), 1060-1066. Web.
Akhavan, B. J., Khanna, N. R. & Vijhani, P. (2020) Amoxicillin. StatPearls Publishing. Web.
Faitelson, Y., Boaz, M. & Dalal, I. (2018). Asthma, family history of drug allergy, and age predict amoxicillin allergy in children. Journal of Allergy and Clinical Immunology, 6(4), 1363-1367. Web.
Labrosse, R., Barrios, J. L., Picard, M., Begin, P. & Samaan, K. (2019) Skin test boosting effect in amoxicillin allergic children. Journal of Allergy and Clinical Immunology, 143(2). Web.
Labrosse, R., Paradis, L., Lacombe-Barrios, J., Samaan, K., Graham, F., Paradis, J., Begin, P. & Des Roches, A. (2018). Efficacy and safety of 5-day challenge for the evaluation of nonsevere amoxicillin allergy in children. The Journal of Allergy and Clinical Immunology: In Practice, 6(5), 1673-1680. Web.