Can foods one is not allergic to exacarbate atopic dermatitis?

Question

Several physicians (incl. two profesors in allergology, regarded among highest authorities in allergology in my country) told me and insisted that people with atopic dermatitis must avoid certain foods for the rest of their lives, even if one is not allergic to these foods. The precise list of exclusions varies from doctor to doctor, but common elements include nuts, cocoa, chocolate, beer, wine, citrus fruit and others, in addition to other exclusions crafted for each patient. According to these physicians these foods are known to exacarbate atopic dermatitis in some non-specific ways, since atopic dermatitis is a complex disease which cannot be reduced to a simple IgE mediated allergy. I am not certain that I understand the theory correctly (as I mainly hearing the recommendation rather than the underlying theories), but perhaps the explanation may be that the lack of filaggrin associated with the disease makes the skin vulnerable to various irritants both from the outside and from the inside of the body (such as substances found in foods) thereby introducing food intolerances that are distinct from food allergies (and therefore will not show up in allergy tests) but nonetheless trigger skin flares. Note that these physicians do not mean the controversial IgG mediated intolerances.

I find it somehow surprising.

I spent a few days searching the internet, but I can't seem to be able to find much relevant information.

• The AAAAI explicitly states: "of particular note, eliminating a variety of foods from the diet that you are not allergic to is rarely helpful in patients with eczema". This seems to be a direct negation of this theory of the aforementioned professors, but sadly this is just a simple negation, with no explanation nor discussion.
  • The ASCIA says that in general if one is not allergic to a food one needs to consume this food daily since this is how the body maintains the tolerance to a food. Therefore, if the above AAAAI claim is true, then treating AD patients with strict elimination diets that go far beyond food allergies may be beyond superfluous, it may cause significant harm to these patients, it would seem to me.
• At the same time the AAAAI expresses similar concerns wrt. alcohol: "alcohol can decrease the threshold level to trigger an allergic reaction, can decrease the time to develop an allergic reaction, and increase severity. However, alcohol itself is an unlikely allergen." This doesn't yet outright contradict the previous statement (since alcohol is not a food), but is dangerously close to such a contradiction.
• Likewise, the AAAAI says that some spice can cause skin rash even though one is not allergic to this spice. I am not certain if spice qualifies as food - if it doesn't then this statement again falls short of outright contradicting the statement from the first bullet, but is dangerously close.
• Medycyna Praktyczna (a website officially recommended by the Polish Society of Allergology) says that food intolerances can be allergic or non-allergic, that non allergic food intolerances encompass substances that cause allergy symptoms and are released in non specific ways as well as trigger mechanism such as coffee or wine.
• These two articles from the National Eczema Association (1 and 2) present a somewhat moderate approach: they say that the line between food allergies and sensitivities is blurred in inflammatory diseases such as atopic dermatitis and that therefore certain foods may trigger the immune system and cause eczema or astma without causing the severe symptoms of bonafide allergies such as anaphylaxis, that such intolerances will not always show up on allergy tests and that for some people a restrictive diet may be helpful with alleviating the symptoms, but it does not work for everyone.
• Poradnik Zdrowe (I'm not sure about the quality of this website) lists certain foods that may exacarbate allergic diseases even though the patient is not allergic to them. For example, pickles, raspberries, sausages, cheese, smoked fish contain high amounts of histamine according to this website, while chocolate, wine and herring are high in tyramine. Also tartrazine (commonly used as food a food coloring) is supposed to stimulate the production of histamine by the body.

I am frustrated by my inability to find any definitive answers, since it seems that everyone says something different. It would seem to me that the scientific community is split apart, research has not yet converged to any conclusions accepted by the majority of scientists. Is this the case? Since trying to find answers in the internet only left me with more questions, could someone briefly outline the current state of the art with regard to the issue whether or not a elimination diets that go far beyond confirmed food allergies help alleviate eczema?

Answer 1

With medicine, no single person is omniscient to all the necessary facts, and physiological differences between individuals complicate this. That said, here are a few general points that would address your question from my perspective.

Allergies

Allergies come in multiple forms, ranging from severe, anaphylactic reactions to mild sensitivities. The severest forms are in the minority, and most allergic responses are not immediate nor life-threatening.

Testing

Doctors most often test for the severe allergic reactions. This can be done via an IgE RAST test. But there is another important test which should be done to check for the less immediate allergic reactions, which are the majority of allergies: IgG. The IgG test will show results for allergic responses that are not so immediate.

Alternative

An individual can actually test for allergies without the help of a blood test by carefully controlling the diet and recording any allergic response. With foods, owing to the length of time for them to transit the GI tract, they can be "in the system" for about three days. To test for an allergy, one may start with a food that is least likely to be an allergen, e.g. rice, and consume only plain rice for three days. Then, assuming the allergic responses have not occurred, add one more food to the diet and watch to see if any signs of a reaction occur within about the next 8 hours. Absent any reaction, add another food, and so on. Keep a careful record of the foods, times, and reactions, and follow this record to determine which food(s) are problematic.

Allergies are induced by proteins since the immune system response is toward proteins. But even an oil, such as soybean oil, may induce an allergic response if the processing of that oil left traces of proteins. It takes very little exposure to induce an allergic response. In most cases, a minute amount of the allergen will have the same effect as a large quantity of it. If you are allergic to milk, you may as well have a whole glass of it as to have a little non-dairy creamer with calcium caseinate (milk protein) as one of its minor ingredients.

Lifetime of an Allergy

Allergies can have a limited lifespan, depending on how the individual handles them. If one has zero exposure to a specific allergen for a considerable length of time--say 18 months or more, the immune response may weaken to the point of "forgetting" the allergy. I know of a beekeeper who developed an anaphylactic reaction to the bee stings and had to quit working with bees. He carried an "anakit" (shot of epinephrine) with him for several years, just in case he were to be stung. After ten years had passed, he received an accidental sting, but had no reaction. His body had forgotten the allergy.

Why Some Foods Banned for Life?

Any food to be avoided for life implies a non-allergy-based rationale. Chocolate, for example, has some phytochemicals that are similar to our hormones and which have an effect on skin, and many people have experienced increased symptoms of acne or eczema after consuming chocolate. This is not, however, due to an allergic reaction per se.

Another possibility is that one has consumed too much of something like zinc, and the skin condition is triggered as a result of the body's elevated levels. Zinc is ordinarily considered an essential nutrient, and many people experience zinc deficiency; but zinc can also become toxic if one is overexposed to it. A mineral test, such as a hair-mineral analysis (HMA) test, may be indicated to determine if this might be a factor.

Conclusion

With so many possible variables, answers may be hard to find. I would suggest looking more at minerals, vitamins, and longer-term allergic reactions such as those identified by an IgG test.

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References to Some Scientific Publications on Benefits to IgG Testing

Alpay K, Ertas M, Orhan EK, Üstay DK, Lieners C, Baykan B. Diet restriction in migraine, based on IgG against foods: a clinical double-blind, randomized, crossover trial. Cephalalgia. 2010;30(7):829-837. doi: 10.1177/0333102410361404.

Atkinson W, Sheldon TA, Shaath N, Whorwell PJ. Food elimination based on IgG antibodies in irritable bowel syndrome: a randomized controlled trial. Gut. 2004;51(10):1459-1464. doi: 10.1136/gut.2003.037697.

Aydinlar EI, Dikmen PY, Tiftikci A, Saruc M, Aksu M, et al. IgG-based elimination diet in migraine plus irritable bowel syndrome. Headache. 2013;53(3):514-525. doi: 10.1111/j.1526-4610.2012.02296.x.

Bentz S, Hausmann M, Piberger H, Kellermeier S, Paul S, et al. Clinical relevance of IgG antibodies against food antigens in Crohn’s disease: a double-blind crossover diet intervention study. Digestion. 2010;81(4):252-264. doi: 10.1159/000264649.

Bernardi D, Borghesan F, Faggian D, Bianchi FC, Favero E, et al. Time to reconsider the clinical value of immunoglobulin G4 to foods. Clin Chem Lab Med. 2008;46(5):687-690. doi: 10.1515/CCLM.2008.131.

Cai C, Shen J, Zhao D, Qiao Y, Xu A, et al. Serological investigation of food specific immunoglobulin G antibodies in patients with inflammatory bowel diseases. PLoS ONE. 2014;9(11):1-8. doi: 10.1371/journal.pone.0112154. [includes Crohn’s and Ulcerative colitis]

Drisko J, Bischoff B, Hall M, McCallum R. Treating Irritable Bowel Syndrome with a food elimination diet followed by food challenge and probiotics. J Am Coll Nutr. 2006;25(6):514-522. doi: 10.1080/07315724.2006.10719567.

Fritscher-Ravens A, Pflaum T, Mösinger M, et al. Many Patients With Irritable Bowel Syndrome Have Atypical Food Allergies Not Associated With Immunoglobulin E. Gastroenterology. 2019;157(1):109-118 doi: 10.1053/j.gastro.2019.03.046.

Gunasekeera V, Mendall MA, Chan D, Kumar D. Treatment of Crohn’s Disease with an IgG4-Guided Exclusion Diet: A Randomized Control Trial. Dig Dis Sci. 2016;61(4):1148-1157. doi: 10.1007/s10620-015-3987-z.

Jian L, Anqi H, Gang L, Litian W, Yanyan X, et al. Food exclusion based on IgG antibodies alleviates symptoms in ulcerative colitis. Inflammatory Bowel Diseases. 2018; 24(9):1918-1925. doi: 10.1093/ibd/izy110.

Mitchell N, Hewitt CE, Jayakody S, Islam M, Adamson J, Watt I, et al. Randomised controlled trial of food elimination diet based on IgG antibodies for the prevention of migraine like headaches. Nutr J. 2011;10:85. doi: 10.1186/1475-2891-10-85.

Rajendran N, Kumar D. Food-specific IgG4-guided exclusion diets improve symptoms in Crohn’s disease: a pilot study. Colorectal disease. 2011;13(9):1009-1013 doi: 10.1111/j.1463-1318.2010.02373.x.

Sub Lee H, Jae Lee K. Alterations of food-specific serum IgG4 titers to common food antigens in patients with Irritable Bowel Syndrome. J Neurogastroenterol Motility. 2017;23(4):578-584. doi: 10.5056/jnm17054.

Uhde M, Caio G, De Giorgio R, Green PH, Volta U, Alaedini A. Subclass Profile of IgG Antibody Response to Gluten Differentiates Non-Celiac Gluten Sensitivity from Celiac Disease. Gastroenterology. 2020; S0016-5085(20)34992-1. doi: 10.1053/j.gastro.2020.07.032.

Wang G, Ren J, Li G, Hu Q, Gu G, Ren H. The utility of food antigen test in the diagnosis of Crohn’s disease and remission maintenance after exclusive enteral nutrition. Clinics and Research in Hepatology and Gastroenterology. 2018;42(2):145-152. doi: 10.1016/j.clinre.2017.09.002.

Xie Y, Zhou G, Xu Y, He B, Wang Y, Ma R, et al. Effects of Diet Based on IgG Elimination Combined with Probiotics on Migraine Plus Irritable Bowel Syndrome. J Pain Res. 2019;7890461. doi: 10.1155/2019/7890461.

Zar S, Benson M, Kumar D. Food-specific Serum IgG4 and IgE titers to common food antigens in Irritable Bowel Syndrome. Am J Gastroenterol. 2005;100(7):1550-1557. doi: 10.1111/j.1572-0241.2005.41348.x.

Zuo XL, Li YQ, Li WJ, Guo YT, Lu XF, et al. Alterations of food antigen-specific serum immunoglobulins G and E antibodies in patients with irritable bowel syndrome and functional dyspepsia. Clin Exper Allergy. 2007;37:823-830. doi: 10.1111/j.1365-2222.2007.02727.x.