Projects
033 – Dental PEARLS: Dental Penicillin Allergy ReferraL study
- Chief Investigator A: Dr Leanne Teoh
- Chief Investigator B: Prof Michael McCullough
- Chief Investigator C: A/Prof Jason Trubiano
Introduction
Penicillin allergy is the most commonly reported drug class allergy, with 10% of the Australian population having a penicillin allergy label. However, of the 10% of patients with a reported penicillin allergy label, only 1% of patients have a true penicillin allergy; the other 9% of penicillin allergy labels are in error. This is due to the penicillin allergy label being erroneous – the patient either had a non-immune-mediated reaction (e.g. a side effect such as nausea/diarrhoea) that was incorrectly recorded as an allergy, or the allergy has worn off. Fifty percent of penicillin allergies wear off after 5 years. Patients with a penicillin allergy label are associated with receiving more toxic, expensive and suboptimal antibiotics with higher rates of adverse effects. They are also associated with having higher rates of antibiotic resistant infections, increased rates of hospitalisation and lengthier hospital stays. Patients with an incorrect penicillin allergy label also tend to receive broader spectrum antibiotics, which contributes to the public health problem of antibiotic resistance. Patients who present with a penicillin allergy label are as frequent in dentistry as in medicine. Because of this, in dental practice, appropriate enquiry into a patient’s reported penicillin allergy with advice to refer for testing has been included in the latest national dental Therapeutic Guidelines.
Aim
- To determine the proportion of penicillin allergic patients with a low-risk penicillin allergy phenotype assessed by dentists.
- To determine the proportion of patients referred by dentists with a low-risk phenotype that can have their penicillin allergy label removed by testing
- To assess this method for dentists to appropriately screen and refer patients for penicillin allergy de-labelling as there is no current method for dentists do to this.
Rationale
In dentistry, patients who report a penicillin allergy will usually receive clindamycin, as recommended by the national dental guidelines. Clindamycin is associated with a significantly higher rate of serious adverse effects than narrow and moderate spectrum penicillin antibiotics, in particular C. difficile infections. In overgrowth, C. difficile produces toxins that cause inflammation of the gut lining, and can cause anywhere between a mild to severe, life-threatening infectious diarrhoea that requires hospitalisation. While this is associated with all antibiotic use, it is particularly associated with clindamycin and other broad-spectrum antibiotics. Thus, in dental practice, assessment of a patient’s penicillin allergy label is important for future antibiotic use and reducing exposure of the patient to antibiotic adverse effects.
Methodology
Participants will be invited to use the Qualtrics tool to screen eligible patients for this study, and refer these patients to the testing centre. Patients will be considered eligible for referral if the meet the following criteria:
- Have a reported penicillin allergy;
- Have a score of 0-2 using the PEN-FAST calculator; and
- Require antibiotic prophylaxis, or have one or more of the following medical conditions: diabetes, immunosuppressed (medications for autoimmune conditions, cancer, corticosteroids, transplant patients, chemotherapy), had previous GI surgery, age>65 years, prior C. difficile infection or splenectomy.
If their patient is eligible, the dentist will email the Austin Hospital Antibiotic Allergy Testing Centre with the standard referral form for the patient’s details. These patients will be fast-tracked to the low-risk allergy testing clinic at the Austin Hospital Centre for Antibiotic Allergy and Research.
The results of antibiotic allergy testing will be communicated back to the referring dentist via email.
What are the expected outcomes?
It is anticipated the results of this study will demonstrate the ability of dentists to appropriately screen patients, and the value of having dentists involved in referring appropriate patients for penicillin allergy testing and subsequent de-labelling. This can inform national policies about referrals by dentists for penicillin allergy testing in the future and ensure dentists can be responsible for appropriate screening and referral of their patients. The validation of the screening tool will then allow it to become part of future dental guidelines.
