Conference Roundup Highlights From Spring 2021 Virtual Medical Meetings American Academy of Dermatology, American Association of Neurology, ACC, ENDO 2021, and NAPNAP 2021
The majority (85% to 90%) of adverse drug reactions are predictable based upon the pharmacologic properties of the medicine and the dose given to the patient. Some patients indicate that they can not be given penicillin due to a “family history of penicillin allergy,” but having relatives with a penicillin allergy (without confirmation) is not a valid contraindication, Dr Wendling said. The drug provocation test (DPT) is the gold standard for penicillin allergy testing, although in cases when a clinician is concerned about anaphylaxis, skin testing may be done first. During DPT the patient is given an age-appropriate dose of amoxicillin and observed for 60 minutes.The test is designed to rule out an IgE-mediated immediate reaction, Dr Wendling said. An extended challenge can help identify a T-cell-mediated DHR, she noted. An extended challenge may also help increase confidence in removing penicillin allergy
from the patient’s record so that penicillin can be prescribed for future infections. Since penicillin is the treatment of choice for several common infections, understanding whether or not a patient has a true allergy to the medication is crucial to optimizing patient outcomes. Neither side effects nor family history should be used as a reason to not prescribe penicillin if the patient has an infection that warrants treatment with antibiotics, Dr Wendling said. Diagnostic testing can confirm whether or not the patient has a life-threatening allergy to penicillin. Using second-line antibiotics to avoid prescribing penicillin is associated with increased hospitalization, morbidity, antibiotic resistance, and cost of care. Public health and patient outcomes are dependent on decreasing the number of patients who are not truly allergic to penicillin but receive second-line therapies to avoid the medication, Dr Wendling concluded.
TABLE. Types of Drug Hypersensitivity Reactions Type I
Type II
Type III
Type IV
Mechanism
IgE-mediated
IgG-mediated and complement formation
IgG or IgM and complement activation with immune complex deposition
T-cell mediated
Onset
Immediate
Delayed
Delayed
Delayed
Outcome
Anaphylaxis
Cytopenia
Serum sickness-like reaction
Maculopapular rash
Ig, immunoglobulin
14 THE CLINICAL ADVISOR • MAY/JUNE 2021 • www.ClinicalAdvisor.com
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PINPOINTING PENICILLIN ALLERGY IN THE PEDIATRIC POPULATION Understanding the characteristics and prevalence of adverse reactions to penicillin in the pediatric population is crucial to optimizing patient outcomes and limiting cost of care, reported Trisha Wendling, DNP, APRN, CPNP-PC, during a presentation at the National Association of Pediatric Nurse Practitioners Annual Meeting (NAPNAP 2021), held March 24 to March 27, 2021. Penicillin allergy is the most commonly reported drug allergy, noted Dr Wendling. Although penicillin allergy is reported in 10% to 20% of hospitalized patients, the true prevalence is estimated to be approximately 4% to 5%. Most children (95%) who develop a rash when given amoxicillin are not truly allergic to the drug when re-exposed. In those cases, noted Dr Wendling, the rash is likely in response to a virus or an interaction between a virus and the antibiotic. Even in cases when the rash is caused by an allergic reaction, 50% of these children will tolerate amoxicillin after 5 years and 80% will tolerate amoxicillin after 10 years. Out of all reported reactions to penicillin, just 5% are anaphylaxis; 38% are rashes, 18% are hives, 9% are angioedema, 6% are gastrointestinal upset, and 5% are itching. Just over one-quarter (26%) of reactions are “unknown.” Approximately 10% to 15% of all adverse drug reactions are drug hypersensitivity reactions (DHRs; Table).
