What Are Beta-Lactam Antibiotics?

Antibiotics are medicines used to treat infections caused by bacteria. They do not help infections caused by viruses. One type of BL antibiotic is called penicillin, and other types are called cephalosporins. BL antibiotics are the medicine given the most to children and are also the most common cause of medicine reactions in children.

What Are Skin Reactions?

A skin reaction is a problem with the skin such as itchiness, a rash or swelling. It can be caused by different things:

• Allergy to a BL antibiotic.
• Result of an infection (from bacteria or a virus).
• A combined situation where an infection can be from a virus, and the virus can interact with medicine to cause a skin reaction.

Why Is It Important to Be Sure about an Allergy Diagnosis?

Parents/caregivers may notice that their child has a skin reaction at the time of being unwell with an infection and being given BL antibiotics. Then, whenever the child needs antibiotics in the future, they may mention this to the doctor, and it is incorrectly noted in the child’s medical records as an allergy.

The next time the child is sick, even though they may not have an allergy to BL antibiotics, the doctor may choose to give the child an alternative antibiotic.

However, alternative antibiotics may not be as specific for treating an infection, meaning they can be less effective. This results in a cycle of poorer health and higher medical costs, both for the child and, on a larger scale, the general community.

Therefore, the authors report it is essential to know if a child really is allergic to BL antibiotics.

How Do You Confirm Allergy?

A suspected allergy can be tested for by finding out about the child’s medical history and completing some medical tests. These tests usually involve giving a small amount of the substance and seeing how the body reacts. This can be by putting some on the skin (a skin prick test (SPT) or intradermal test (IDT)) or eating some (oral challenge test (OCT)). For BL antibiotic allergy, the best test is an OCT. Recent research recommends that if a child has already had a mild skin reaction, it is sensible to complete an OCT.

How Did the Authors Test for the Allergy?

The authors tested 214 children who had experienced mild skin reactions after taking BL antibiotics. They carried out both skin tests and an OCT on all the children and observed the reactions.

What Were the Results of the Allergy Tests?

It was discovered that 23 of the 214 children (10.7%) had a BL allergy. In other words, the remaining 191 children did not have an allergy, even though they had a skin reaction at the time of taking the BL antibiotics.

How Did the Authors Examine the Risk Factors?

The authors then wanted to try and find out whether they could predict the allergy in ways that would avoid doing the testing. They examined the nature of the reactions, such as whether they happened immediately or non-immediately, and the type of reaction, such as rash, itchiness, or something severe that made the child unwell. They also recorded information on family history of allergy, the child’s gender, and the child’s personal health history.

They used statistical methods to work out what might be a risk factor. This included comparing the children with proven BL allergy to the children who had a mild skin reaction but no allergy. The only factor that made the children with a BL allergy stand out was if they also had confirmed allergies to other medication. The other factors were the same for children with and without BL allergy.

What Did This Study Show?

In this study, BL allergy was confirmed in 10.7% of children who described a mild skin reaction related to BL antibiotics. This means that the true rate of BL allergy resulting in a mild skin reaction is lower than that reported by parents. It also means that BL allergy is often wrongly diagnosed when only a child’s skin reaction type and timing is used to make a decision.

In other words, mild skin reactions in children with suspected BL allergy are likely to be due to viral infections or a combined situation where a virus can interact with medicine to cause a skin reaction. Therefore, an allergy test is required to be sure about – and mostly likely rule out – BL allergy.

Take-Home Message

If a child has a skin reaction after taking BL antibiotics, it is likely that they are not allergic to the antibiotic. They need to have an allergy test to be sure. However, if the child already has confirmed allergies to other medications, this increases the chance that they may also be allergic to BL antibiotics.

Note: This post is based on an article that is not open-access; i.e., only the abstract is freely available.