Multiple Drug Hypersensitivity Syndrome

Study Overview
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Brief Summary
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Background: Multiple drug hypersensitivity syndrome (MDH) is defined as confirmed drug hypersensitivity reactions (DHRs) to at least 2 chemically and pharmacologically unrelated drugs. Reports of MDH are scarce and poorly specified and studies which diagnose MDH on the basis of positive allergy tests are lacking. Objective: To evaluate retrospectively the frequency and characteristics of MDH patients in a large database. Methods: All the patients who consulted and were tested in our Allergy Unit between September 1996 and February 2018, with confirmed MDH will be included. Clinical history and allergy work-up results will be extracted from our Drug Allergy and Hypersensitivity Database (DAHD). The frequency of MDH will be calculated, MDH patients will be described, the most frequent associations of DHRs will be identified and analysed.

Official Title
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Multiple Drug Hypersensitivity Syndrome in a Large Database

Conditions
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Drug Allergy

Participation Criteria
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Eligibility Criteria
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Inclusion criteria: Patients who consulted at our allergy clinic (University Hospital of Montpellier, France) Between September 1996 and February 2018 with a clinical history suggestive of DHR Who completed a tailored drug allergy work-up, (including a drug allergy questionnaire, skin tests (STs) and drug provocation tests (DPTs)) and were diagnosed with MDH. Exclusion criteria: the DHR was due to a single component contained in 2 different drug formulations in composed drugs; there was possible cross-reactivity between the responsible drugs; (iv) the patient had positive but non standardized nor validated (i.e. possibly irritant) these STs were followed by a negative DPT; DPTs with placebo were positive; (vii) doubtful tests were repeated and eventually considered negative; a single DHR was associated with one or more non-drug related contact allergies; DPTs elicited subjective manifestations (i.e., isolated pruritus, headache, isolated abdominal pain); non-specific histamine release was suspected (e.g., chronic spontaneous - desensitization, rather than a diagnostic work-up was preferred in order to meet the urgent therapeutic needs of individual patients (HIV infected patients, cardiac patients).
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To measure retrospectively the frequency of MDH patients in our database. | The frequency of MDH patients (percentage) in the allergic group of patients will be calculated as the number of MDH patients divided by the number of monoallergic patients (frequency of MDH patients in allergic population) | 1 day | 
| To measure retrospectively the frequency of MDH patients in our database | The frequency of MDH in common population will be calculated by will be calculated as the number of MDH patients divided by the number of patients that underwent diagnostic drug allergy testing within the same time frame (frequency of MDH patients in the whole population | 1 day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To describe the MDH population, identify the most frequent associations of DHR | In this MDH patients population we will : Count the number of female and male patient according to their sex (No unit) | 1 day | 
| To describe the MDH population, identify the most frequent associations of DHR | In this MDH patients population we will : Most frequent associations of DHR (No unit) | 1 day | 
| To describe the MDH population, identify the most frequent associations of DHR | In this MDH patients population we will : Count and classify the different form of DHR according to their severity with the Ring and Messsmer and Regiscar study group scoring. (No unit) (ex: number of patient with grade III anaphylaxis or number of patient with DRESS syndrome ) | 1 day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Multiple Drug Hypersensitivity, drug hypersensitivity, antibiotics, drug provocation tests, skin tests