The Link - December 2025

Penicillin Allergy Prevalence and Mislabeling

Around 10% of Americans report a penicillin allergy, yet only about 1% has a true allergy when tested. Mislabeling often occurs due to confusion between side effects, viral rashes, and allergic reactions, and sometimes caregivers mistakenly believe that a family history of penicillin allergy means the child is penicillin allergic. Importantly, even true IgE-mediated allergies wane over time—50% resolve within five years and 80% within 10 years.

Case Presentation:

A previously healthy 10-year-old girl presented with a three-week history of a progressively spreading rash. Her parents first noticed several small “chicken pox–like” bumps on her chest, abdomen and buttocks four weeks prior. Since onset, the lesions have become more numerous and spread to her neck, face, back, arms, legs, hands and feet. The individual bumps have persisted, with some increasing in size, and the eruption has become more confluent in areas.

The child describes mild pruritus. She was evaluated by her pediatrician who thought she had pityriasis rosea and was prescribed hydrocortisone 2.5% ointment once daily for the past two weeks, which has provided partial relief of itch but no visible improvement in the rash. She also takes oral hydroxyzine at night, which helps with sleep and itch.

Around the time the rash began, she experienced a sore throat that resolved spontaneously. She denies fever, malaise, joint pain, stiffness or myalgias. There has been no blistering, bleeding, ulceration or oozing. She has not started any new medications and has had no recent travel, exposures or vaccinations.

She is otherwise healthy. She lives with her parents and siblings. There is no family history of psoriasis or other chronic skin conditions.

A throat culture obtained in clinic grew group A Streptococcus (GAS).

Recent data suggests that between 40% and 80% of parents search online about their child’s symptoms before going to the doctor. They may even come to their appointments with a preformed idea of what their child has and compare what their pediatrician or subspecialist says to what they have read online. And parents are not the only ones who do this. Many health care workers, students and even doctors may do the same. But what are the attendant risks? As we have an obligation to educate patients and their parents, make accurate diagnoses, and provide evidence-based care to avoid harm and serve the child’s best interests, we should know more ourselves. Let’s look at the risks of online health information.

Chagas disease, or American trypanosomiasis, has long been considered a disease from “south of the border,” relevant in the United States mostly because of large numbers of immigrants from mainland Latin America. However, a recent article in Emerging Infectious Diseases led to a brief surge of publicity by suggesting that instead of considering Chagas disease nonendemic in the United States, it should be acknowledged that vector-borne transmission occurs domestically, though at a low level (hypoendemic). Cases of autochthonous (domestically acquired) vector-borne Chagas disease in the United States (Figure 1) have been uncommonly (28 cases documented from 1955 to 2015, mostly in Texas), but steadily reported and include at least one case with transmission apparently occurring in Missouri. Human cases (including the case in Missouri) are now being detected as a result of blood donor screening, which was first implemented in 2007. Cases in dogs are more common and widespread, having been documented in 23 states, including 451 canine cases in Texas from 2013 to 2015.

Children experience on average three to six upper respiratory tract infections (URIs) per year, mostly in the fall and winter. As a result, many pediatric patients scheduled for anesthesia or sedation currently have or recently had a URI. Frequently, general practitioners are the first people approached by families about whether an upcoming procedure needs to be postponed, and URIs remain the most common causes of procedure cancellation. This is related to the risk of perioperative respiratory adverse events (PRAEs) due to the hyperreactivity of the pulmonary system. PRAEs include breath holding, desaturation, bronchospasm, laryngospasm and need for supplemental oxygen that may require an unplanned admission or an escalation in the level of care. These risks must be balanced against urgency and the type of procedure, severity and duration of symptoms, and the patient’s other comorbidities.