Food allergy causes eczema

Eczema is closely associated with food allergy.
The more severe, and the more early onset eczema, the more likely to be a food allergy.
All eczema children need to be tested for food allergy.
Skin prick tests can identify many of these food allergens.
Non-IgE reactions need IgG antibody measurements.
All babies and children with eczema need to be tested for food allergy.
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Recommendation 

There is a vast amount of medical research data that clearly demonstrates that food allergy is a major factor in eczema in childhood.  If your child has troublesome eczema, then we suggest that you get a full assessment for food allergy/ intolerance.  We offer this service at The Childrens Clinic | Allergy Centre, Christchurch.

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Food allergy & eczema: the link has been proven

Two thirds (65%) of children with atopic dermatitis / eczema have milk/egg/wheat/soy/nut  allergy. 

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Eczema and food allergy: linked!

The research evidence is so strong – so why the controversy?
When we see a child with severe eczema (atopic dermatitis), it is 
our goal is to have their skin near perfect within 12 weeks.  Often we can achieve this.

Eczema (in children) often caused by food allergy

The medical evidence, without-a-shadow-of-a-doubt, shows that food allergy and eczema are strongly linked.  Oddly, this is the complete opposite to what most dermatologists will tell you. Why is this so? I don’t know.  Perhaps it a case of only seeing what you are looking for.

For instance, Kartina, one of my mums, cries out:

“My son’s ex dermatologist clearly hasn’t read anything that’s ever been written [about food allergy]! Was told straight up that food allergies and eczema have nothing to do with each other. Funny, once we found what he was allergic to and removed it, his eczema is nearly but all gone! His incompetence is why we will NOT be returning to his practice.”

Sadly, at The Children Centre (http://www.thechildrensclinic.co.nz/cms), Christchurch, we hear parents comment like this everyday.  Contrary to this dermatology dogma, our experience is that most (80%) children who are troubled by eczema do indeed have food allergy triggers.  When you detect their problematic foods, you have found a solution to their eczema.  Most of the eczema children who come to our clinic get hugely better because we pay close attention to their food allergy.

All children who have eczema get tested for food allergy at our clinic.

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Loads of clinical experience

As a paediatric allergist and gastroenterologist, I have spent my medical career in the allergy field.  My philosophy is to solve my patient’s problems.  For eczema, this means seeing eczema as a symptom – not as a stand-alone disease.  Although many people do have a genetic propensity to develop eczema, there is usually a trigger or cause for it to become manifest: foods in the younger, and environmental allergens and gluten in the older patients. 

I have written up my allergy approach to eczema in a book: “Eczema! Cure it!” (available in print, and as an ebook) http://www.smashwords.com/books/view/47087.  It is my opinion that every baby/child/adult with eczema needs full allergy testing and then action. 

The mothers know

As a junior doctor in the hospital, I would talk to the mothers who had babies with severe eczema. In those days, these children were admitted to hospital under the dermatologist for intensive steroid and antibiotic treatment. Many of these mothers would tell me that some foods they were offering were causing of the bad outbreaks – especially milk, egg and wheat. If this was true, this meant that these babies could be treated (and cured) for their underlying disease rather than just concentrate on dressing the skin.

Enthusiastically, I applied to set up the clinical trial using the double-blind food challenge technique (this was in 1978).  However, my senior pediatric colleagues were negative and skeptical. They told me that food allergy was “a figment of the parent’s imagination”.  Nevertheless, with 126 children and their willing parents, we successfully carried out this study. We did find a link with eczema.  We did find significant relationships between egg/milk allergy reactions, and with positive skin tests to these foods, and with atopic illness (including eczema/ atopic dermatitis).

(see paper: “Egg and cows’ milk allergy in children.” Ford, Fergusson. Arch Dis Child. 1980;55(8):608-10).
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1627029/?tool=pubmed

After this gratifying experience (30 years ago) I have continued to investigate all eczema children for food allergy, gluten sensitivity and inhalant allergy.  By paying close attention to these underlying triggers, these children get very much better, their families are happier and have less stress: and a reduced need for on-going steroid usage.

What has surprised me is that with the research of numerous others that show this eczema-food link, that there remains doubt, skepticism and disbelief.  Why is this so?

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Food allergy very common in children

A recent research paper by Wang & Sampson (J Clin Invest. 2011;121(3):827-35, http://www.ncbi.nlm.nih.gov/pubmed/21364287) declare food allergy to be very common.

They say: “Food allergies affect up to 6% of young children and 3%-4% of adults. They encompass a range of disorders that may be IgE and/or non-IgE mediated, including anaphylaxis, pollen food syndrome, food-protein-induced enterocolitis syndrome, food-induced proctocolitis, eosinophilic gastroenteropathies, and atopic dermatitis (eczema). Many complex host factors and properties of foods are involved in the development of food allergy.”

Food allergy is extremely common. However, most doctors will not consider food allergy in their diagnostic list – only as a last resort.  But symptoms are often treated in isolation, without understanding underlying causes.  Often symptoms are attributed wrongly to viral illness.  A community study looked at the difficulties faced by children in getting a diagnosis of cow’s milk allergy. It took an average of 18 community doctor visits to make the eventual cow’s milk allergy diagnosis, and average time to diagnosis was 4 months.  Surely, as it is so common, food allergy should be a routine item on every doctor’s (including dermatology) diagnostic list. If so, these children would get prompt diagnosis and treatment.

It is clear that every one (children and adults) with on-going symptoms, including eczema (atopic dermatitis) should to be assessed for food allergy.

What have other researchers found?

My food allergy and eczema research is not an isolated piece of work. All research papers looking for the food-allergy-eczema-link find it.  It has been demonstrated over and over that most children with severe eczema have food allergy.

Research papers in Allergy/ Immunology journals report up to a half (35— 90%) of eczema babies have food allergy.  The more severe the eczema, the more likely there is to be underlying food allergy/ intolerance.  By contrast, reports in dermatology papers find lower levels of association – but they still do report a definite relationship (about 7—30%).  This discrepancy is probably due underlying bias of the enrolled patients.

Notes:
The terms “atopic dermatitis (AD)” and “eczema” mean the same thing.
Food allergy predominantly affects children rather than adults.
Every country that looks for it, does find the food-eczema link.

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References: 15 studies proving the food-eczema link

Here are 15 studies, from many countries, that have documented the relationship between food allergy and eczema. I give the reference and links to each paper, and a summary of their work.  They are listed from those with a strong link, to those with weaker associations.

1. Strong link. 70%. “A double-blind controlled crossover trial of an antigen-avoidance diet in atopic eczema.”
D.J. Atherton, J.F. Soothill. The Lancet, 1978;311(8061):401-403.
http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(78)91199-6/abstract

Studied 20 children (aged 2-8 years) with atopic eczema completed a twelve-week, double-blind, controlled, crossover trial of an egg and cows’ milk exclusion diet.  Response was assessed in terms of eczema activity: 14 of these 20 (70%) patients responded more favourably to the antigen-avoidance diet than to the control diet.

2. Strong link. 84%. “Food hypersensitivity and atopic dermatitis: evaluation of 113 patients.”
Sampson, McCaskill.   J Pediatr. 1985;107(5):669-75.
http://www.ncbi.nlm.nih.gov/pubmed/4056964

“Evaluated 113 patients with severe atopic dermatitis for food hypersensitivity with double-blind placebo-controlled oral food challenges: 63 (56%) children experienced 101 positive food challenges; skin symptoms developed in 85 (84%) challenges, gastrointestinal symptoms in 53 (52%), and respiratory symptoms in 32 (32%). Egg, peanut, and milk accounted for 72% of the hypersensitivity reactions induced. History and laboratory data were of marginal value in predicting which patients were likely to have food allergy. When patients were given appropriate restrictive diets based on oral food challenge results, approximately 40% of the 40 patients re-evaluated lost their hypersensitivity after 1 or 2 years, and most showed significant improvement in their clinical course compared with patients in whom no food allergy was documented. These studies demonstrate that food hypersensitivity plays a pathogenic role in some children with atopic dermatitis. Appropriate diagnosis and exclusionary diets can lead to significant improvement in their skin symptoms.”

3.  Strong link. “Food allergy and atopic dermatitis: how are they connected?”
Heratizadeh and others. Curr Allergy Asthma Rep. 2011:11(4):284-91. Germany.
Division of Immunodermatology and Allergy Research, Department of Dermatology and Allergy, Hannover Medical School, Germany.
http://www.ncbi.nlm.nih.gov/pubmed/21614611

They write: “Early food sensitization has been found to be significantly associated with atopic dermatitis (AD).  Three different patterns of clinical reactions to food allergens in AD patients have been identified: 1) immediate-type symptoms, 2) isolated eczematous late-type reactions, and 3) combined reactions. In children, allergens from cow’s milk, hen’s egg, soy, wheat, fish, peanut, or tree nuts are primarily responsible for allergic reactions.”

4.  Strong link.  “Food allergy and atopic dermatitis in infancy: an epidemiologic study.”
D. J. Hill, C. S. Hosking. Pediatric Allergy and Immunology. 2004:15 (5),421–427. Australia.
http://www.ncbi.nlm.nih.gov/pubmed/15482517
http://onlinelibrary.wiley.com/doi/10.1111/j.1399-3038.2004.00178.x/full

They found: “The relative risk of an infant with atopic dermatitis having IgE-mediated food allergy is 5.9 (that is a six-fold difference) for the most severely affected eczema group. There is a strong association between IgE-mediated food allergy and atopic dermatitis in this age group.”

5. Strong link.  “Atopic Dermatitis and food hypersensitivity reactions.” 
A.W. Burks and others, Paediatrics, 132(1):132-6 1998. USA.
http://www.ncbi.nlm.nih.gov/pubmed/9470014

They concluded: “Most children with atopic dermatitis have food allergy that can be diagnosed by a prick skin test for the seven foods.  Seven foods (milk, egg, peanut, soy, wheat, cod/catfish, cashew) accounted for 89% of the positive food challenges. By use of screening prick skin tests for these seven foods we could identify 99% of the food allergic patients correctly.”

6. Strong link.  “Patterns of sensitization in infants and its relation to atopic dermatitis.” Jøhnke et al. Pediatr Allergy Immunol. 2006;17(8):591-600. Denmark.
http://www.ncbi.nlm.nih.gov/pubmed/17121587

They followed a cohort of 562 unselected newborns looking for food allergy sensitization and atopic dermatitis (eczema). They concluded “persistent positive skin prick test reactivity for food allergens, high-level of food allergy sensitization and multiple food allergy were clearly associated with Atopic Dermatitis.”

7. Strong link. 90.5%.  “The incidence of food allergy in atopic dermatitis.”  
Ogura and others. Arerugi, 2001:50(7): 621-8. Japan.
http://www.ncbi.nlm.nih.gov/pubmed/11554066

They report: “the incidence of food allergy in eczema was 90.5%, and with the main food culprits egg allergy, cow’s milk allergy, soy bean allergy, wheat allergy, rice allergy were 83.5%, 51.5%, 33.5%, 20.0%, 2.5% respectively in the 200 cases.”

8. Strong link. 65-83%.  “The association of atopic dermatitis in infancy with immunoglobulin E food sensitization.”
Hill et al. J Paediatrics 2000:137(4): 475-479. Australia.
http://www.ncbi.nlm.nih.gov/pubmed/11035824

Concluded: “Infants with severe atopic dermatitis have rates of IgE food sensitisation of 83% at 6 months, and 65% at 12 months. IgE food sensitisation is a major risk factor for the presence of AD in infancy.”

9. Strong link. 53%. “Predictors of positive food challenge outcome in non-IgE-mediated reactions to food in children with atopic dermatitis.”
Niggemann et al. J Allergy Clin Immunol. 2001 Dec;108(6):1053-8. Germany.
http://www.ncbi.nlm.nih.gov/pubmed/11742288

Atopic dermatitis is frequently associated with food allergy. In general, clinically manifested food allergy is regarded as IgE mediated. However, there are some children with food allergy for whom IgE hypersensitivity cannot be proven.

208 food challenges (DBPCFC) were performed in 139 children (median age, 13 months) with atopic dermatitis and suspected food-related clinical symptoms: 111 (53%) of 208 oral food challenge results were assessed as positive.

10. Strong link. 50%. “Milk allergy/intolerance and atopic dermatitis in infancy and childhood.”
E. Novembre, A. Vierucci  Allergy. 2001;56 Suppl 67:105-8.  Italy.
http://www.ncbi.nlm.nih.gov/pubmed/11298023

They say: “Atopic dermatitis (AD) is one of the most common symptoms of as cow’s milk allergy/intolerance (CMPA/CMPI). Approximately one third of AD children have a diagnosis of CMPA/CMPI according to elimination diet and challenge tests, and about 40–50% of children <1 year of age with CMPA/CMPI have AD.” 

11. Moderate link. “Epidemiology and prevention of cow’s milk allergy.”
Host A & Halken S. Allergy 1998;56 (suppl 45): 111-113
http://onlinelibrary.wiley.com/doi/10.1111/j.1399-3038.1994.tb00352.x/abstract

“Symptoms suggestive of Cow’s milk protein allergy (CMPA) may be encountered in about 5–15% of infants. Most infants with CMPA develop symptoms before one month of age, often within one week after introduction of cow’s milk based formula. About 50%–70% have cutaneous symptoms, 50–60% gastrointestinal symptoms, and about 20–30% respiratory symptoms. In exclusively breast-fed infants with CMPA severe atopic eczema is a predominant symptom.”

 12. Moderate link. 35%.  “The role of food allergy in atopic dermatitis.”
Greenhawt. Allergy Asthma Proc. 2010:31(5):392-7. USA
(University of Michigan Food Allergy Center, USA)
http://www.ncbi.nlm.nih.gov/pubmed/20929606

“As food allergy is a known provoking cause of Atopic Dermatitis (AD) in a subset of affected children.” They carried out “a literature search of PubMed and Medline to review the epidemiology and pathophysiology of AD, with special focus on the role of food allergy in the development of AD.  They confirm: “Atopic dermatitis (AD) affects ?10% of children. Food allergens readily provoke AD in ?35% of patients, as proven through double-blind placebo-controlled food challenge studies. Milk, egg, wheat, soy, and peanut account for 75% of the cases of food-induced AD.”

 13. Moderate link. 30%.  “The role of food allergy in atopic dermatitis.”
HaukPJ. Curr Allergy Asthma Rep. 2008;8(3):188-94. USA.
http://www.ncbi.nlm.nih.gov/pubmed/18589836

“Atopic dermatitis (AD) is a chronic, pruritic, inflammatory skin disease affecting more than 10% of all children. Sensitization to foods triggers isolated skin symptoms in about 30% of children. These symptoms include immediate reactions within minutes after ingesting food without exacerbation of AD and early and late exacerbations of AD. It is important to identify clinically relevant sensitizations to foods using skin prick tests, a specific IgE blood test, and food challenges to initiate appropriate dietary interventions.”

14. Weak link. 7%.  “Does food allergy cause atopic dermatitis? Food challenge testing to dissociate eczematous from immediate reactions.”
Rowlands et al.  Dermatol Ther. 2006;19(2):97-103. USA
Department of Dermatology, Portland,USA.
http://www.ncbi.nlm.nih.gov/pubmed/16669992

Only 1 of 15 (7%) of patients hospitalized for management of severe, unremitting atopic dermatitis (AD) was shown to have food allergy associated with eczema. Patients were closely observed for evidence of pruritus, eczematous responses, or IgE-mediated reactions. If results were inconsistent, double-blind, placebo-controlled food challenge was performed.

Atopic dermatitis, even in the highest-risk patients, is rarely induced by foods. Immediate IgE-mediated food reactions are common in atopic dermatitis patients; such reactions are rapid onset, typically detected outside the clinic, and must be distinguished from eczematous reactions. Diagnosis of food-induced eczema cannot be made without food challenge testing. Such tests can be practical and useful for dispelling unrealistic assumptions about food allergy causation of atopic dermatitis.”

 15. Weak link. 3%. “Egg allergy in patients over 14 years old suffering from atopic eczema.”
Celakovská et al.  Int J Dermatol. 2011;50(7):811-8. Czech Republic.
http://www.ncbi.nlm.nih.gov/pubmed/21699516

Occurrence of egg allergy in patients over 14 years old suffering from atopic eczema, was studied – to see if egg allergy can deteriorate the course of atopic eczema: 179 patients with atopic eczema were studied (average age 26 years).

“Egg allergy was confirmed in 11 (6%) patients: only 6 of these patients (3%) had a clear improvement in their eczema after the elimination of egg.  Egg allergy may play an important role in the worsening of atopic eczema acting as a triggering-exacerbating factor in a minority of patients.”

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Gluten known to cause skin disease

It has been known for a long time that gluten is can cause skin disease.  The classic example is a very itchy rash called “Dermatitis herpetiformis” (DH).  It usually affects the elbows, knees, buttocks, scalp, and back.  It begins as little bumps that then change into little blisters.  People say that they are driven mad by the itching.

Gluten can cause itchy skin/ eczema

DH is caused by an immune reaction to gluten in the skin.  Microscopic clumps of gluten (called immune-complexes) get deposited just under the skin.  This creates that itchy rash.  These tiny particles of gluten can take years to clear up once you start on a gluten-free diet.  It may take up to ten years before you make a full recovery. 

Humbert and his dermatology colleagues (2006:  http://www.ncbi.nlm.nih.gov/pubmed/16436335) wrote this about gluten and skin disease:

“Gluten sensitivity, with or without celiac disease symptoms and intestinal pathology, has been suggested as a potentially treatable cause of various diseases.  There have been numerous reports linking celiac disease with several skin conditions.

Dermatitis herpetiformis is actually a skin manifestation of celiac disease.  Autoimmune diseases, allergic diseases, psoriasis and miscellaneous diseases have also been described with gluten intolerance.  Dermatologists should be familiar with the appraisal of gluten sensitive enteropathy and should be able to search for an underlying gluten intolerance.  Serological screening by means of anti-gliadin AGA), anti-endomysial (EMA) and tissue-transglutaminase (tTG) antibodies should be performed.

Gluten intolerance gives rise to a variety of dermatological manifestations which may benefit from a gluten-free diet.”

This is an important statement.  I have discovered that gluten intolerance is very common in children (and adults) with troublesome persistent eczema.  It is certainly well worth looking for.  In our clinic, after the age of two, gluten is the most common food trigger for eczema.

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Verdict

There is overwhelming medical research evidence that eczema/atopic dermatitis is closely associated with food allergy.
The more severe the eczema, and the younger the child, the more likely it is that food(s) is triggering the eczema.
In older children and adults gluten sensitivity needs to be considered.

Dr Rodney Ford  Nov 2011

The Childrens Clinic | Allergy Centre, Christchurch