Food AllergyTROPHAPRICKNCT06872996
Trophallergen Prick Tests (PT) : Influence of Food Sample Shelf Life on the Reproducibility of PT Results
A study testing Prick-test in people with Food Allergy, run by Centre Hospitalier Régional d'Orléans at 1 site in France.
Trial summary
Prick tests (PT) are the standard skin tests used in the investigation of immediate IgE-mediated food allergies. Their use as a first-line tool in allergological investigations is strongly recommended by the European Academy of Allergy and Clinical Immunology (EAACI). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Food Allergy
- What is being tested?
- Prick-test
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 100 participants
- Where
- 1 siteFrance
- Study dates
- 10 Apr 2025to 10 Oct 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Aged 18 and over.
- Having a diagnosis of food allergy(ies) due to one or more of the food allergen studied, previously made by an allergologist, of grade 2 to 3 according to the Ring and Messmer classification.
- Having given consent to participate in the study.
- The diagnosis is made by the allergologist of the department due to the presence of a compatible clinical history implicating the tested allergen, the presence of evidence of sensitization to the allergen (positive prick-test and/or positive specific IgE assays), or even a positive oral allergen reintroduction test.
Who cannot join
- Anaphylactic reaction dating less than 6 weeks
- Hospitalization for asthma in the past 3 months
- History of grade 4 anaphylactic reaction according to the Ring and Messmer classification.
- Systemic antihistamine treatment in the 7 days preceding the test
- Systemic beta-blocker treatment on the day of the test.
- Protected person (under guardianship or curatorship)
Show all 10Show fewer
- Person under judicial supervision
- Persons deprived of liberty
- Person not affiliated with a social security insurance
- Pregnant or breastfeeding women
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
France1 site, 1 recruiting
- Recruiting
Centre Hospitalier Universitaire d'Orléans
Orléans, 45067
Minaxi Dr PATEL, PhD, 238613223 ext. +33, minaxi.patel@chu-orleans.fr
Julien Dr Lefrançois, PhD, 238691383 ext. +33, julienlefr@yahoo.fr
About this study
Prick tests (PT) are the standard skin tests used in the investigation of immediate IgE-mediated food allergies. Their use as a first-line tool in allergological investigations is strongly recommended by the European Academy of Allergy and Clinical Immunology (EAACI). These tests involve locally reproducing histamine release manifestations in the epidermis by superficially introducing an allergen to confirm or rule out its role in the onset of clinical symptoms compatible with an allergy. During the diagnostic management and follow-up of patients with food allergies, the technique used is the "prick to prick" method, due to the lack of reliable access to many standardized commercial food extracts. This method involves piercing the food with a sterile lancet (to deposit food content on its surface) and then making a superficial skin puncture with the same device on the anterior surface of the forearm to introduce a tiny fraction of the food and its proteins into the epidermis, where mast cells are present. Simultaneously, a positive control and a negative control are performed. The tests are read after 15 to 20 minutes by measuring the size in millimeters of the resulting papules and erythema. A PT for the tested allergen is considered positive if the average diameter of the resulting papule is 3 mm or more and/or at least half the size of the positive control papule. The procedure is well-tolerated, allowing it to be performed at any age, in both hospital and outpatient settings. The risk of a systemic reaction has been evaluated at 0.008%, with no severe reactions observed.
This method, performed with native foods (unprocessed food, uncontaminated foods), either raw or cooked (depending on the nature of the allergen being tested), is preferred over the use of commercial extracts (standardized commercial allergen preparations) due to its better sensitivity and specificity, the high cost of commercial extracts, and the lack of commercial extracts for certain foods. For practical reasons, given the wide variety of possible allergens, and to most accurately reproduce the exposure that caused the reaction, the most common approach is to ask the patient to bring their own foods for testing. These foods should be brought in a fresh state. However, situations where the patient is offered a food PT but does not have fresh native foods are common. Indeed, many patients forget to bring them. Similarly, during a consultation to explore a respiratory or drug allergy, the interview may lead to the detection of a food allergy that needs to be tested at the same time. Given the delays in allergology consultations, the severity of food allergy symptoms, and the potential risk of delayed diagnosis, all allergists involved in managing food allergies are led to create a library of food samples stored either in a dry state (e.g., nuts, peanuts, cereal flours) or frozen for perishable foods (meats, shellfish, fruits, vegetables). To our knowledge, after reviewing the literature, no guidelines for best practices regarding the storage of these food samples for PT purposes have been established by scientific societies. Moreover, while the impact of freezing and thawing methods on the denaturation of food proteins is known, the effect of freezing and its duration on the sensitivity and specificity of PT is poorly understood.
The objective of our study is to evaluate the reproducibility of PT results between those performed with fresh foods and those performed with preserved foods at different storage dates in participants who have experienced anaphylaxis of at least grade 2 according to the Ring and Messmer classification.
Read the detailed description
Interventional, exploratory, prospective, single-center clinical study comparing for each patient included, at the same time, the results of prick tests carried out with fresh native food allergens and those carried out with native foods stored for prolonged period (in the freezer or dry dependig on the nature of the product) and for different shelf lives.
A native food is a raw food not contaminated by other foods. It is said to be fresh if it has not been subject to a prolonged preservation technique such as freezing or canning. The native food can be raw or cooked depending on the nature of the food and the nature of the allergic protein tested.
In our study the patient is his own witness. Carrying out all tests in a single session makes it possible to avoid analysis biases related to intra-individual variabilities in reactivity encountered during prick tests carried out on different dates (patient included only once in the study, no re-inclusion possible). In our study, several foods can be tested for the same patient depending on the number of food allergies that the patient has.
The completion of the study does not change the follow up methods for patients who are already offered prick tests as part of their allergic pathology. The study lasts approximately 30 minutes for each patient, while the prick tests are carried out. Their follow up is carried out by nurses of the allergology department for 30 minutes from the completion of the prick tests and this, under the responsibility of the allergist doctor of the department whose presence is obligatory when performing these tests.
Participants will be fully and honestly informed, in understandable terms, about the objectives and constraints of the study, the potential risks incurred, the necessary monitoring and safety measures, and their rights to refuse to participate in the study or to withdraw at any time.
All this information is provided in an information form given to the patient. The patient's written consent will be obtained by the investigator, a junior doctor, or a representative doctor before any procedure specific to the study.
As this is a pilot, exploratory, monocentric study, and given that Orléans University Hospital receives approximately 50 patients per year (who meet the eligibility criteria), it is planned to include 100 patients in the study over a maximum period of 30 months.
A clinical research associate (ARC) mandated by the sponsor will ensure the proper conduct of the study, the collection of generated data, its documentation, recording, and reporting, in accordance with the Standard Operating Procedures implemented within Orléans University Hospital and in compliance with Good Clinical Practices as well as the applicable legislative and regulatory provisions.
Participants will be fully and honestly informed, in understandable terms, about the objectives and constraints of the study, the potential risks incurred, the necessary monitoring and safety measures, and their rights to refuse to participate in the study or to withdraw at any time.
All this information is provided in an information form given to the patient. The patient's written consent will be obtained by the investigator, a junior doctor, or a representative doctor before any procedure specific to the study.
- Conditions
- Food Allergy
- Being tested
- Prick-test
- Keywords
- Prick test, Skin test, Trophallergen, Food sample, Fresh, Frozen, Fruit, vegetables, Meat, Alpha-gal, Arachide, Leguminous plant, Milk, Nuts, Fish, Seafood
- Medical subject headings
- Food Hypersensitivity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Prick-testDiagnostic test
Several foods may be tested for the same participant depending on the number of food allergies the patient has. PT are performed using the "prick-to-prick" method with lancets, in a single session per patient, using fresh and preserved native foods. Simultaneously, a positive control and a negative control are performed. The PT are performed and read by nursing or medical staff trained in the technique.
Participants' clinical follow-up is performed continuously for 30 minutes from the performance of the prick-tests and under the responsibility of the allergologist doctor, whose presence is mandatory during the performance of these tests.
For meat, fruit, vegetable, leguminous plant, milk, seafood and fish tests will be performed with fresh products and with products preserved for 3 months as well as with products preserved for 6 months [-15 days; +15 days].
For dry foods (nuts and peanuts), tests will be performed with products harvested over 3 separate and consecutive seasons.
| Study group | Role | What they receive |
|---|---|---|
| Food allergies arm | Experimental | The participants are their own control. Performing all tests in a single session avoid analysis biases related to intra-individual variability in reactivity encountered during prick-tests performed on various dates (patient included only once in the study, no possible re-inclusion). Receives: Diagnostic Test: Prick-test |
What is being measured
The primary outcome is the main question the study is designed to answer.
Average diameter (mm) of the resulting papules obtained from PT performed with fresh foods, with preserved foods at different storage durations and with positives and negatives controls.
Average diameter of the papule : average between the smallest diameter and the largest diameter of the papule.
Test interpretable if the average diameter of the positive histamine control papule is 3 mm or more and if the average diameter of the negative saline control papule is less than 3 mm.
Test considered positive if the average diameter of the papule obtained with the allergen is 3 mm or more and/or half or more of the size of the positive control papule.
Test considered negative if the average diameter of the papule obtained with the allergen is less than 3 mm.
Measured: The tests are read 15 to 20 minutes after the food is pricked onto the participants' skin
Secondary outcomes (1)
The Histamine Equivalent Prick index diameter (HEP-index diameter) calculated during PT performed with fresh foods and foods stored for different durations
The HEP-index diameter (Histamine Equivalent Prick index diameter) obtained by dividing the average diameter of the papule induced by the allergen by the average diameter of the positive histamine control papule.
Test interpretable if the average diameter of the positive histamine control papule is 3 mm or more and if the average diameter of the negative saline control papule is less than 3 mm.
Test considered positive if HEP-index diameter is 0.6 or more. Test considered negative if HEP-index diameter is less than 0.6.
Measured: The tests are read 15 to 20 minutes after the food is pricked onto the participants' skin.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Mar 2025
- Study start10 Apr 2025
- Primary completion10 Oct 2027 (estimated)
- Study completion10 Oct 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (17)Papers the sponsor has linked to this study.
- Other trials for Food AllergyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Participants are recruited, day by day, according to the modalities and eligibility criteria during consultations or day hospitalizations in the allergology department of Orléans University Hospital for the follow-up of their food allergy. All participants present one or more food allergy(ies) followed at Orléans University Hospital and agree to participate in the TROPHAPRICK study. If a potential patient attends a consultation without their native foods, the investigator will not include them in the study. However, they may participate in the study during a subsequent follow-up consultation with the investigator (if recruitment is still ongoing). The duration of the inclusion period is maximum 30 months (upon inclusion of the 100th patient) Each participant follow-up duration is 30 minutes (maximum 1 hour) The total research duration is 30 months maximum. The end of the study is defined as the date of the last visit of the last patient.
- Masking
- None (open label)
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Centre Hospitalier Régional d'Orléans
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06872996
- Sponsor's protocol ID
- CHUO-2024-19
- Acronym
- TROPHAPRICK
- Status last verified
- Dec 2025
- First submitted
- 7 Mar 2025
- Last updated
- 30 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Santos AF, Riggioni C, Agache I, Akdis CA, Akdis M, Alvarez-Perea A, Alvaro-Lozano M, Ballmer-Weber B, Barni S, Beyer K, Bindslev-Jensen C, Brough HA, Buyuktiryaki B, Chu D, Del Giacco S, Dunn-Galvin A, Eberlein B, Ebisawa M, Eigenmann P, Eiwegger T, Feeney M, Fernandez-Rivas M, Fisher HR, Fleischer DM, Giovannini M, Gray C, Hoffmann-Sommergruber K, Halken S, Hourihane JO, Jones CJ, Jutel M, Knol E, Konstantinou GN, Lack G, Lau S, Marques Mejias A, Marchisotto MJ, Meyer R, Mortz CG, Moya B, Muraro A, Nilsson C, Lopes de Oliveira LC, O'Mahony L, Papadopoulos NG, Perrett K, Peters RL, Podesta M, Poulsen LK, Roberts G, Sampson HA, Schwarze J, Smith P, Tham EH, Untersmayr E, Van Ree R, Venter C, Vickery BP, Vlieg-Boerstra B, Werfel T, Worm M, Du Toit G, Skypala I. EAACI guidelines on the diagnosis of IgE-mediated food allergy. Allergy. 2023 Dec;78(12):3057-3076. doi: 10.1111/all.15902. Epub 2023 Oct 10.
PubMed 37815205Riggioni C, Ricci C, Moya B, Wong D, van Goor E, Bartha I, Buyuktiryaki B, Giovannini M, Jayasinghe S, Jaumdally H, Marques-Mejias A, Piletta-Zanin A, Berbenyuk A, Andreeva M, Levina D, Iakovleva E, Roberts G, Chu D, Peters R, du Toit G, Skypala I, Santos AF. Systematic review and meta-analyses on the accuracy of diagnostic tests for IgE-mediated food allergy. Allergy. 2024 Feb;79(2):324-352. doi: 10.1111/all.15939. Epub 2023 Nov 27.
PubMed 38009299Henzgen M, Ballmer-Weber BK, Erdmann S, Fuchs T, Kleine-Tebbe J, Lepp U, Niggemann B, Raithel M, Reese I, Saloga J, Vieths S, Zuberbier T, Werfel T; German Society of Allergology and Clinical Immunology (DGAKI); Physicians' Association of German Allergologists (ADA); Society of Pediatric Allergology (GPA); Swiss Society of Allergology. Skin testing with food allergens. Guideline of the German Society of Allergology and Clinical Immunology (DGAKI), the Physicians' Association of German Allergologists (ADA) and the Society of Pediatric Allergology (GPA) together with the Swiss Society of Allergology. J Dtsch Dermatol Ges. 2008 Nov;6(11):983-8. doi: 10.1111/j.1610-0387.2008.06889.x. English, German.
PubMed 18992038Rance F, Juchet A, Bremont F, Dutau G. Correlations between skin prick tests using commercial extracts and fresh foods, specific IgE, and food challenges. Allergy. 1997 Oct;52(10):1031-5. doi: 10.1111/j.1398-9995.1997.tb02427.x.
PubMed 9360758Brockow K, Romano A, Blanca M, Ring J, Pichler W, Demoly P. General considerations for skin test procedures in the diagnosis of drug hypersensitivity. Allergy. 2002 Jan;57(1):45-51. No abstract available.
PubMed 11991289Ruethers T, Johnston EB, Karnaneedi S, Nie S, Nugraha R, Taki AC, Kamath SD, Williamson NA, Mehr SS, Campbell DE, Lopata AL. Commercial shellfish skin prick test extracts show critical variability in allergen repertoire. Allergy. 2023 Dec;78(12):3261-3265. doi: 10.1111/all.15853. Epub 2023 Aug 21. No abstract available.
PubMed 37602511Patti ML, De Rose C, Brancato F, Gambacorta A, Miceli Sopo S. Sensitivity of prick test with walnut commercial extracts and of prick by prick with raw walnut compared with open food challenge in walnut allergy. Acta Biomed. 2021 Apr 30;92(S1):e2021067. doi: 10.23750/abm.v92iS1.10043.
PubMed 33944826Codreanu F, Moneret-Vautrin DA, Morisset M, Guenard L, Rance F, Kanny G, Lemerdy P. The risk of systemic reactions to skin prick-tests using food allergens: CICBAA data and literature review. Eur Ann Allergy Clin Immunol. 2006 Feb;38(2):52-4.
PubMed 16711536Lee S, Jo K, Jeong HG, Choi YS, Kyoung H, Jung S. Freezing-induced denaturation of myofibrillar proteins in frozen meat. Crit Rev Food Sci Nutr. 2024;64(5):1385-1402. doi: 10.1080/10408398.2022.2116557. Epub 2022 Sep 2.
PubMed 36052640Garriga T, Guilarte M, Luengo O, Guillen M, Labrador-Horrillo M, Fadeeva T, Sala A, Cardona V. Frozen fruit skin prick test for the diagnosis of fruit allergy. Asian Pac J Allergy Immunol. 2010 Dec;28(4):275-8.
PubMed 21337912Terlouw S, van Boven FE, Borsboom-van Zonneveld M, de Graaf-In 't Veld T, Gerth van Wijk R, van Daele PLA, van Maaren MS, Kuijpers JHSAM, Veenbergen S, de Jong NW. Comparison of skin prick test and prick-to-prick test with fruits and vegetables in the diagnosis of food allergy. Clin Transl Allergy. 2024 Jul;14(7):e12375. doi: 10.1002/clt2.12375.
PubMed 38970153Begin P, Des Roches A, Nguyen M, Masse MS, Paradis J, Paradis L. Freezing does not alter antigenic properties of fresh fruits for skin testing in patients with birch tree pollen-induced oral allergy syndrome. J Allergy Clin Immunol. 2011 Jun;127(6):1624-6.e3. doi: 10.1016/j.jaci.2011.01.028. Epub 2011 Mar 16. No abstract available.
PubMed 21411128van der Valk JP, Gerth van Wijk R, Hoorn E, Groenendijk L, Groenendijk IM, de Jong NW. Measurement and interpretation of skin prick test results. Clin Transl Allergy. 2016 Feb 23;6:8. doi: 10.1186/s13601-016-0092-0. eCollection 2015.
PubMed 26909142Warren CM, Sehgal S, Sicherer SH, Gupta RS. Epidemiology and the Growing Epidemic of Food Allergy in Children and Adults Across the Globe. Curr Allergy Asthma Rep. 2024 Mar;24(3):95-106. doi: 10.1007/s11882-023-01120-y. Epub 2024 Jan 12.
PubMed 38214821Dribin TE, Motosue MS, Campbell RL. Overview of Allergy and Anaphylaxis. Emerg Med Clin North Am. 2022 Feb;40(1):1-17. doi: 10.1016/j.emc.2021.08.007. Epub 2021 Oct 29.
PubMed 34782082
Study at a glance
From the registry record, last updated by the sponsor on 30 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Trophallergen Prick Tests (PT) : Influence of Food Sample Shelf Life on the Reproducibility of PT Results
- ClinicalTrials.gov ID
- NCT06872996
- Acronym / sponsor ID
- TROPHAPRICK / CHUO-2024-19
- Conditions
- Food Allergy
- Keywords
- Prick test, Skin test, Trophallergen, Food sample, Fresh, Frozen, Fruit, vegetables
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- Centre Hospitalier Régional d'OrléansUniversity, hospital or other
- Study start
- 10 Apr 2025 (actual)
- Primary completion
- 10 Oct 2027 (estimated)
- Study completion
- 10 Oct 2027 (estimated)
- First posted
- 12 Mar 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Prick tests (PT) are the standard skin tests used in the investigation of immediate IgE-mediated food allergies. Their use as a first-line tool in allergological investigations is strongly recommended by the European Academy of Allergy and Clinical Immunology (EAACI). These tests involve locally reproducing histamine release manifestations in the epidermis by superficially introducing an allergen to confirm or rule out its role in the onset of clinical symptoms compatible with an allergy. During the diagnostic management and follow-up of patients with food allergies, the technique used is the "prick to prick" method, due to the lack of reliable access to many standardized commercial food extracts. This method involves piercing the food with a sterile lancet (to deposit food content on its surface) and then making a superficial skin puncture with the same device on the anterior surface of the forearm to introduce a tiny fraction of the food and its proteins into the epidermis, where mast cells are present. Simultaneously, a positive control and a negative control are performed. The tests are read after 15 to 20 minutes by measuring the size in millimeters of the resulting papules and erythema. A PT for the tested allergen is considered positive if the average diameter of the resulting papule is 3 mm or more and/or at least half the size of the positive control papule. The procedure is well-tolerated, allowing it to be performed at any age, in both hospital and outpatient settings. The risk of a systemic reaction has been evaluated at 0.008%, with no severe reactions observed.
This method, performed with native foods (unprocessed food, uncontaminated foods), either raw or cooked (depending on the nature of the allergen being tested), is preferred over the use of commercial extracts (standardized commercial allergen preparations) due to its better sensitivity and specificity, the high cost of commercial extracts, and the lack of commercial extracts for certain foods. For practical reasons, given the wide variety of possible allergens, and to most accurately reproduce the exposure that caused the reaction, the most common approach is to ask the patient to bring their own foods for testing. These foods should be brought in a fresh state. However, situations where the patient is offered a food PT but does not have fresh native foods are common. Indeed, many patients forget to bring them. Similarly, during a consultation to explore a respiratory or drug allergy, the interview may lead to the detection of a food allergy that needs to be tested at the same time. Given the delays in allergology consultations, the severity of food allergy symptoms, and the potential risk of delayed diagnosis, all allergists involved in managing food allergies are led to create a library of food samples stored either in a dry state (e.g., nuts, peanuts, cereal flours) or frozen for perishable foods (meats, shellfish, fruits, vegetables). To our knowledge, after reviewing the literature, no guidelines for best practices regarding the storage of these food samples for PT purposes have been established by scientific societies. Moreover, while the impact of freezing and thawing methods on the denaturation of food proteins is known, the effect of freezing and its duration on the sensitivity and specificity of PT is poorly understood.
The objective of our study is to evaluate the reproducibility of PT results between those performed with fresh foods and those performed with preserved foods at different storage dates in participants who have experienced anaphylaxis of at least grade 2 according to the Ring and Messmer classification.
Detailed description
Interventional, exploratory, prospective, single-center clinical study comparing for each patient included, at the same time, the results of prick tests carried out with fresh native food allergens and those carried out with native foods stored for prolonged period (in the freezer or dry dependig on the nature of the product) and for different shelf lives.
A native food is a raw food not contaminated by other foods. It is said to be fresh if it has not been subject to a prolonged preservation technique such as freezing or canning. The native food can be raw or cooked depending on the nature of the food and the nature of the allergic protein tested.
In our study the patient is his own witness. Carrying out all tests in a single session makes it possible to avoid analysis biases related to intra-individual variabilities in reactivity encountered during prick tests carried out on different dates (patient included only once in the study, no re-inclusion possible). In our study, several foods can be tested for the same patient depending on the number of food allergies that the patient has.
The completion of the study does not change the follow up methods for patients who are already offered prick tests as part of their allergic pathology. The study lasts approximately 30 minutes for each patient, while the prick tests are carried out. Their follow up is carried out by nurses of the allergology department for 30 minutes from the completion of the prick tests and this, under the responsibility of the allergist doctor of the department whose presence is obligatory when performing these tests.
Participants will be fully and honestly informed, in understandable terms, about the objectives and constraints of the study, the potential risks incurred, the necessary monitoring and safety measures, and their rights to refuse to participate in the study or to withdraw at any time.
All this information is provided in an information form given to the patient. The patient's written consent will be obtained by the investigator, a junior doctor, or a representative doctor before any procedure specific to the study.
As this is a pilot, exploratory, monocentric study, and given that Orléans University Hospital receives approximately 50 patients per year (who meet the eligibility criteria), it is planned to include 100 patients in the study over a maximum period of 30 months.
A clinical research associate (ARC) mandated by the sponsor will ensure the proper conduct of the study, the collection of generated data, its documentation, recording, and reporting, in accordance with the Standard Operating Procedures implemented within Orléans University Hospital and in compliance with Good Clinical Practices as well as the applicable legislative and regulatory provisions.
Participants will be fully and honestly informed, in understandable terms, about the objectives and constraints of the study, the potential risks incurred, the necessary monitoring and safety measures, and their rights to refuse to participate in the study or to withdraw at any time.
All this information is provided in an information form given to the patient. The patient's written consent will be obtained by the investigator, a junior doctor, or a representative doctor before any procedure specific to the study.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Participants are recruited, day by day, according to the modalities and eligibility criteria during consultations or day hospitalizations in the allergology department of Orléans University Hospital for the follow-up of their food allergy. All participants present one or more food allergy(ies) followed at Orléans University Hospital and agree to participate in the TROPHAPRICK study. If a potential patient attends a consultation without their native foods, the investigator will not include them in the study. However, they may participate in the study during a subsequent follow-up consultation with the investigator (if recruitment is still ongoing). The duration of the inclusion period is maximum 30 months (upon inclusion of the 100th patient) Each participant follow-up duration is 30 minutes (maximum 1 hour) The total research duration is 30 months maximum. The end of the study is defined as the date of the last visit of the last patient.
| Arm | Type | Receives |
|---|---|---|
| Food allergies arm | Experimental | Diagnostic Test: Prick-testThe participants are their own control. Performing all tests in a single session avoid analysis biases related to intra-individual variability in reactivity encountered during prick-tests performed on various dates (patient included only once in the study, no possible re-inclusion). |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Aged 18 and over.
- Having a diagnosis of food allergy(ies) due to one or more of the food allergen studied, previously made by an allergologist, of grade 2 to 3 according to the Ring and Messmer classification.
- Having given consent to participate in the study.
- The diagnosis is made by the allergologist of the department due to the presence of a compatible clinical history implicating the tested allergen, the presence of evidence of sensitization to the allergen (positive prick-test and/or positive specific IgE assays), or even a positive oral allergen reintroduction test.
Key exclusion criteria (10 listed)
- Anaphylactic reaction dating less than 6 weeks
- Hospitalization for asthma in the past 3 months
- History of grade 4 anaphylactic reaction according to the Ring and Messmer classification.
- Systemic antihistamine treatment in the 7 days preceding the test
- Systemic beta-blocker treatment on the day of the test.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Prick-testSeveral foods may be tested for the same participant depending on the number of food allergies the patient has. PT are performed using the "prick-to-prick" method with lancets, in a single session per patient, using fresh and preserved native foods. Simultaneously, a positive control and a negative control are performed. The PT are performed and read by nursing or medical staff trained in the technique. Participants' clinical follow-up is performed continuously for 30 minutes from the performance of the prick-tests and under the responsibility of the allergologist doctor, whose presence is mandatory during the performance of these tests. For meat, fruit, vegetable, leguminous plant, milk, seafood and fish tests will be performed with fresh products and with products preserved for 3 months as well as with products preserved for 6 months [-15 days; +15 days]. For dry foods (nuts and peanuts), tests will be performed with products harvested over 3 separate and consecutive seasons. | Diagnostic test | Food allergies arm |
Primary outcome
Average diameter (mm) of the resulting papules obtained from PT performed with fresh foods, with preserved foods at different storage durations and with positives and negatives controls.
Time frame: The tests are read 15 to 20 minutes after the food is pricked onto the participants' skin
Average diameter of the papule : average between the smallest diameter and the largest diameter of the papule. Test interpretable if the average diameter of the positive histamine control papule is 3 mm or more and if the average diameter of the negative saline control papule is less than 3 mm. Test considered positive if the average diameter of the papule obtained with the allergen is 3 mm or more and/or half or more of the size of the positive control papule. Test considered negative if the average diameter of the papule obtained with the allergen is less than 3 mm.
1 secondary outcome
The Histamine Equivalent Prick index diameter (HEP-index diameter) calculated during PT performed with fresh foods and foods stored for different durations
Time frame: The tests are read 15 to 20 minutes after the food is pricked onto the participants' skin.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Dec 2025.
- Background: PubMed 37815205Santos AF, Riggioni C, Agache I, Akdis CA, Akdis M, Alvarez-Perea A, Alvaro-Lozano M, Ballmer-Weber B, Barni S, Beyer K, Bindslev-Jensen C, Brough HA, Buyuktiryaki B, Chu D, Del Giacco S, Dunn-Galvin A, Eberlein B, Ebisawa M, Eigenmann P, Eiwegger T, Feeney M, Fernandez-Rivas M, Fisher HR, Fleischer DM, Giovannini M, Gray C, Hoffmann-Sommergruber K, Halken S, Hourihane JO, Jones CJ, Jutel M, Knol E, Konstantinou GN, Lack G, Lau S, Marques Mejias A, Marchisotto MJ, Meyer R, Mortz CG, Moya B, Muraro A, Nilsson C, Lopes de Oliveira LC, O'Mahony L, Papadopoulos NG, Perrett K, Peters RL, Podesta M, Poulsen LK, Roberts G, Sampson HA, Schwarze J, Smith P, Tham EH, Untersmayr E, Van Ree R, Venter C, Vickery BP, Vlieg-Boerstra B, Werfel T, Worm M, Du Toit G, Skypala I. EAACI guidelines on the diagnosis of IgE-mediated food allergy. Allergy. 2023 Dec;78(12):3057-3076. doi: 10.1111/all.15902. Epub 2023 Oct 10.
- Background: PubMed 38009299Riggioni C, Ricci C, Moya B, Wong D, van Goor E, Bartha I, Buyuktiryaki B, Giovannini M, Jayasinghe S, Jaumdally H, Marques-Mejias A, Piletta-Zanin A, Berbenyuk A, Andreeva M, Levina D, Iakovleva E, Roberts G, Chu D, Peters R, du Toit G, Skypala I, Santos AF. Systematic review and meta-analyses on the accuracy of diagnostic tests for IgE-mediated food allergy. Allergy. 2024 Feb;79(2):324-352. doi: 10.1111/all.15939. Epub 2023 Nov 27.
- Background: PubMed 18992038Henzgen M, Ballmer-Weber BK, Erdmann S, Fuchs T, Kleine-Tebbe J, Lepp U, Niggemann B, Raithel M, Reese I, Saloga J, Vieths S, Zuberbier T, Werfel T; German Society of Allergology and Clinical Immunology (DGAKI); Physicians' Association of German Allergologists (ADA); Society of Pediatric Allergology (GPA); Swiss Society of Allergology. Skin testing with food allergens. Guideline of the German Society of Allergology and Clinical Immunology (DGAKI), the Physicians' Association of German Allergologists (ADA) and the Society of Pediatric Allergology (GPA) together with the Swiss Society of Allergology. J Dtsch Dermatol Ges. 2008 Nov;6(11):983-8. doi: 10.1111/j.1610-0387.2008.06889.x. English, German.
- Background: PubMed 9360758Rance F, Juchet A, Bremont F, Dutau G. Correlations between skin prick tests using commercial extracts and fresh foods, specific IgE, and food challenges. Allergy. 1997 Oct;52(10):1031-5. doi: 10.1111/j.1398-9995.1997.tb02427.x.
- Background: PubMed 11991289Brockow K, Romano A, Blanca M, Ring J, Pichler W, Demoly P. General considerations for skin test procedures in the diagnosis of drug hypersensitivity. Allergy. 2002 Jan;57(1):45-51. No abstract available.
- Background: PubMed 37602511Ruethers T, Johnston EB, Karnaneedi S, Nie S, Nugraha R, Taki AC, Kamath SD, Williamson NA, Mehr SS, Campbell DE, Lopata AL. Commercial shellfish skin prick test extracts show critical variability in allergen repertoire. Allergy. 2023 Dec;78(12):3261-3265. doi: 10.1111/all.15853. Epub 2023 Aug 21. No abstract available.
- Background: PubMed 33944826Patti ML, De Rose C, Brancato F, Gambacorta A, Miceli Sopo S. Sensitivity of prick test with walnut commercial extracts and of prick by prick with raw walnut compared with open food challenge in walnut allergy. Acta Biomed. 2021 Apr 30;92(S1):e2021067. doi: 10.23750/abm.v92iS1.10043.
- Background: PubMed 16711536Codreanu F, Moneret-Vautrin DA, Morisset M, Guenard L, Rance F, Kanny G, Lemerdy P. The risk of systemic reactions to skin prick-tests using food allergens: CICBAA data and literature review. Eur Ann Allergy Clin Immunol. 2006 Feb;38(2):52-4.
- Background: PubMed 36052640Lee S, Jo K, Jeong HG, Choi YS, Kyoung H, Jung S. Freezing-induced denaturation of myofibrillar proteins in frozen meat. Crit Rev Food Sci Nutr. 2024;64(5):1385-1402. doi: 10.1080/10408398.2022.2116557. Epub 2022 Sep 2.
- Background: PubMed 21337912Garriga T, Guilarte M, Luengo O, Guillen M, Labrador-Horrillo M, Fadeeva T, Sala A, Cardona V. Frozen fruit skin prick test for the diagnosis of fruit allergy. Asian Pac J Allergy Immunol. 2010 Dec;28(4):275-8.
- Background: PubMed 38970153Terlouw S, van Boven FE, Borsboom-van Zonneveld M, de Graaf-In 't Veld T, Gerth van Wijk R, van Daele PLA, van Maaren MS, Kuijpers JHSAM, Veenbergen S, de Jong NW. Comparison of skin prick test and prick-to-prick test with fruits and vegetables in the diagnosis of food allergy. Clin Transl Allergy. 2024 Jul;14(7):e12375. doi: 10.1002/clt2.12375.
- Background: PubMed 21411128Begin P, Des Roches A, Nguyen M, Masse MS, Paradis J, Paradis L. Freezing does not alter antigenic properties of fresh fruits for skin testing in patients with birch tree pollen-induced oral allergy syndrome. J Allergy Clin Immunol. 2011 Jun;127(6):1624-6.e3. doi: 10.1016/j.jaci.2011.01.028. Epub 2011 Mar 16. No abstract available.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Prick-test in people with Food Allergy, run by Centre Hospitalier Régional d'Orléans at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 30 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Minaxi Dr PATEL, PhD (238613223 ext. +33, minaxi.patel@chu-orleans.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Average diameter (mm) of the resulting papules obtained from PT performed with fresh foods, with preserved foods at different storage durations and with positives and negatives controls. (time frame: The tests are read 15 to 20 minutes after the food is pricked onto the participants' skin). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06872996, which also lists 17 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Dec 2025; AzTrials last refreshed its copy on 8 Nov 2026.