Food Patch Testing for IBS
The food allergy testing offered by our centers is a completely novel way of identifying foods that may cause IBS, as shown in our recent pivotal study, Food Patch Testing for Irritable Bowel Syndrome, published in the Journal of the American Academy of Dermatology (Stierstorfer MB, Sha CT, Sasson M. Food Patch Testing for Irritable Bowel Syndrome. J Am Acad Dermatol 2013;68:377-84). Our IBS testing identifies food allergies by looking for small allergic reactions that may occur on your skin after food test materials are placed in contact with your skin for 48 hours (see below). The testing also is useful for individuals suffering from another gastrointestinal condition, eosinophilic esophagitis.
We have carefully selected the foods used in the testing. They are the most common ones known to cause the type of allergic reaction that our study results suggest cause IBS in some individuals. Nearly half the participants in our study who had an allergic skin reaction to at least one food experienced improvement in their IBS symptoms when they avoided the food(s) in question. If you react to one or more foods, and you then avoid the food(s) in question, there is a chance your IBS symptoms might not improve. This would suggest that the foods to which your skin reacted are not playing a role in your gastrointestinal symptoms or that other foods not included in our testing that you are still eating could be contributing to your symptoms as well. There is a chance your skin will not show allergic reactions to any of the foods being tested. If no allergic reactions are found, we feel there is value in knowing that the foods tested are unlikely to be the cause of your IBS symptoms.
Prior research efforts have focused on blood tests measuring antibodies to specific foods. A large consensus expert panel from the National Institute for Allergy and Infectious Diseases recently published their report: Guidelines for the Diagnosis and Management of Food Allergy in the United States (Boyce JA, Arshad SA, Assa’ad A, Bahna SL, Beck LA, Burks AW, et al. J Allergy Clin Immunol. 2010;126:S1–58). They determined these blood tests not to be worthwhile and advised against performing them.
Our testing requires 3 visits to the office within 5 days. Each visit typically takes 30 minutes or less.
Prior to IBS Testing
Avoid direct sun exposure on your back for 4 weeks prior to testing. Sun may decrease your skin’s ability to mount an immune response to the test materials.
Individuals with hair on their upper and/or mid back should shave or wax it off two days before your appointment. Do not use chemical hair removers.
Take a bath or shower the morning you come for your first appointment but do not apply any lotions or other products to your back after the shower.
Day 1 – 121 different food and food additive test materials (see upper row left below) are applied to individual wells aligned on strips of hypoallergenic adhesive tape (upper row middle) and taped to your upper and mid back (upper row right and middle row left). You must keep your upper and mid back dry, avoid excessive sweating, and avoid leaning over/bending your back too much for the next 2 days so that the patch tests stay in place.
Day 3 – The patch tests are removed, the patch test sites are outlined with a black non-permanent marker (middle row right), and the 1st patch test reading performed. At this point, you may bathe as you normally would except that you will be asked to avoid directly washing your back until after the final patch test reading a day or 2 later, so that the black marker lines remain visible until after the final reading.
Day 4 or 5 – You return to the office for the final patch test reading.
With your approval, close-up photographs of your back may be recorded for any positive test reactions (close-up of a typical positive patch test is shown in the last photo). There will be no personally identifiable information on these photos.
If you have an allergic reaction, the specific foods will be identified and you will be given information to help you avoid those specific foods. In our study, almost half the people who had at least one allergic reaction and then avoided the food(s) in question experienced improvement or elimination of their symptoms. Your improvement may occur within 24 hours or possibly longer. If there is no improvement after 1 month of strict avoidance of the foods in question, you would be unlikely to improve at that point, and should consider adding the foods in question back to your diet.
Our involvement in your care is limited to the food patch testing in search for causes or contributing factors for your IBS symptoms. We advise you to continue with your primary care and/or specialist physician for all other matters regarding your IBS symptoms and general medical care.
Who Cannot Participate
If you have any known food allergies, please inform us of them and what type of reaction you have when you eat or touch the food. This may or may not disqualify you from testing eligibility depending on the food(s) to which you are allergic and the type of allergic reaction you have.
Also, you should not undergo the testing if you are pregnant, breastfeeding, have a severe rash, are allergic to adhesive tape, or taking any immunosuppressive medications such as Prednisone, chemotherapy or medications used to prevent organ transplant rejection during the testing or in the week preceding the testing.
For general questions, contact us at info@IBSfoodallergy.com.