De-labeling of Patients With False Diagnosis of Penicillin Allergy

Study Overview
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Brief Summary
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The purpose of this study is to estimate the prevalence of penicillin allergy, evaluate the diagnostic value of the allergologic work-up used in the study, and the health effects of penicillin allergy.

Detailed Description
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Penicillin allergy is the most common of self-reported drug allergies and un-verified penicillin allergy is a significant and growing public health problem. 10% of all patients report penicillin allergy. However, there is large discrepancy between reported penicillin allergy and true allergy. Despite its high prevalence, greater than 90% of such patients are in fact able to tolerate the medication without allergic reactions. In this study patients having a penicillin allergy label will be investigated to confirm or to exclude the allergy diagnosis. The diagnostic value of the allergen test panel and the allergologic work-up will be evaluated. Clinical parameters as well as immunological will be assessed.

Official Title
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Diagnostic De-labeling of Patients With False Diagnosis of Penicillin Allergy: A Tool for Improving Antimicrobial Treatment and Reducing Antimicrobial Resistance

Conditions
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Allergy Drug

Intervention / Treatment
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* Diagnostic Test: Allergy work-up
* Other: Blood samples


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients who are referred to the department of Pulmonary medicine with clinical history suspected of having penicillin allergy. The control group will be healthy adult volunteers with no history of any personal or family history of drug allergy, atopy, inflammatory or autoimmune diseases. Exclusion Criteria: Systemic reactions such as DRESS, any internal organ involvement Clinical history of Type II-III hypersensitivity reaction Severe Type IV hypersensitivity reaction such as Stevens-Johnson syndrome, toxic epidermal necrolysis, DRESS, vasculitis, acute generalized exanthematous pustulosis Chronic idiopathic urticaria on antihistamine maintenance treatment/anti-IgE treatment Medication which can affect the test outcome Active signs of an underlying disease such as uncontrolled asthma Cardiac disease with increased risk of serious anaphylaxis Pregnancy/Breastfeeding Reaction within the last 4-6 weeks

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Interventional Model Description: Patient group consisting of patients labeled as penicillin allergic.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Patients labeled as penicillin allergic<br>Patients labeled as penicillin allergic will be allergologically investigated to confirm/exclude the diagnosis. Allergy work-up will be performed. Blood samples will be obtained.Questionnaire to evaluate the effectiveness of the intervention. | Diagnostic Test: Allergy work-up<br>* Allergy work-up<br>Other: Blood samples<br>* Blood samples<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Prevalence of Penicillin allergy in the studied group | Frequency of true penicillin allergy in the study group | up to 4 years | 
| Negative predictive value of the allergy work- up | If the allergy work-up is negative, drug provocation test with penicillin will be performed. The purpose of the drug challenge is to confirm lack of allergy and confirm the negative predictive value of the allergy work-up. | 3 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Use of b-lactams after negative allergy work-up and development of new drug reactions following negative testing. | Patients going through an allergy workup with negative results, will be retrospectively contacted within one year after investigation. Telephone interview where the following questions will be asked:1) Have you received antibiotic therapy since being seen in the allergy clinic? 2) If you have been treated, what drug did you take? 3) As a result of this, did you have a reaction to the antibiotics? If yes, what kind of reaction have you developed? 4) If you didn't take the drug you were challenged with what was the reason for that? | 12 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Penicillin/b-lactams