I was working in the emergency department of a pediatric hospital. A 2-year-old female with an obvious rash was brought in by her mother, who wondered whether the rash might be chickenpox. I took the child and her mother back to a cubicle and began to take the child’s history. The child was healthy and had no major health problems. Her vaccinations were all current, including the chickenpox vaccine, which made a diagnosis of chickenpox unlikely. She had recently been diagnosed with otitis media (an ear infection) and was on her second-to-last day of antibiotic therapy with amoxicillin, a penicillin-type antibiotic. The child had taken amoxicillin on one other occasion for an ear infection.
Her vital signs were normal, and she did not have a fever. I examined her rash, which covered her face, chest, back, arms, and legs. In fact, it covered almost her entire body except the palms of her hands and soles of her feet. It appeared to be a maculopapular rash, a flat red rash with tiny pimplelike eruptions in the center.
After recording the history and the child’s assessment, I went to find the physician and reported my findings. He told me that he felt he knew what the problem was but would examine the child first to confirm his diagnosis. The physician looked at the patient’s rash and told the mother, “Just as I thought. The rash is a reaction to the amoxicillin your daughter has been taking. We will stop the amoxicillin and the rash should go away in one to two weeks.” The mother was surprised because the child hadn't had a reaction with the first round of treatment with amoxicillin. The physician told her that an amoxicillin rash is considered an adverse reaction to the medication and most likely not an allergy. The mother should report the amoxicillin rash to health care providers in the future, but the antibiotic could still be used to treat future infections.
The child’s ears were checked and the ear infection seemed to have resolved. The child and her mother were discharged with instructions to administer topical steroid cream as needed to help manage the itching.