ALLERGY, HISTAMINE or INTOLERANCE?

Understanding Allergy

True allergy is where your immune system is reacting to either a food or something which is air borne, such as dust, grass, mold, animal dander etc. Search “what is a neti pot?” to learn about the amazing tool that relieves nasal congestion. The response is an over reaction by the immune system producing antibodies known as immunoglobulin E (IgE) and the allergy symptoms which present are usually related to respiratory and skin areas and can include anyone or more of the following:

• asthma
• cough
• wheezing
• nasal drip
• eczema
• hives
• persistent runny nose, itchy, congestion
• hay fever
• anaphylaxis
• itching of the throat, eyelids, face, mouth or tongue

Allergy is more common in children, it’s more permanent than food intolerances and usually is related to one or two isolated foods, and/or pollen, fungus spores, animal dander, mould or medicines. The offenders usually need to be avoided long term. It is important to note that digestive infections can elevate IgE (partiularly worms!). Reactions can occur immediately, but there can be a later reaction about 4 to 6 hours after the initial reaction and persist for days with symptoms like oedema (fluid retention) and inflammation. Studies show that antacids (proton pump inhibitors such as somac or pariet) impair digestion and can lead to elevation in IgE antibodies, considering that this is one of the highest selling drugs on the market it’s probably good to know!

Understanding HISTAMINE Intolerance

Interestingly elevated histamine will present as the same symptoms as those in allergy, but the cause is due to histamine excess. related to an inability of the body to clear histamine, causing an overload. Dietary histamine can be rapidly detoxified normally by enzymes known as Diamine oxidase (DAO) and histamine N-methyltransferase (HNMT), but some people have genetic issues with these enzymes or may be over eating foods which are high in histamine, and the result is impaired histamine degradation, resulting in symptoms mimicking allergic symptoms. This makes it difficult to differentiate between histamine excess and allergy. Here are some of the symptoms.

• diarrhea
• headache
• rhinoconjunctival symptoms
• asthma
• hypotention
• arrhythmia
• urticaria
• pruritus
• flushing

Foods high in histamine include fermented products such as wine, dry sausage, sauerkraut, miso, soy sauce, scombroid type fish and cheese. In those who have these allergy like symptoms and have a negative diagnosis of allergy (IgE) then histamine intolerance should be considered. Learn more on histamine intolerance here.

Understanding Delayed Intolerances

Other types of intolerances are related to antibodies produced by the immune system which cause delayed onset hypersensitivity reactions to foods, which can take several hours or days for a reaction to occur and can persist for weeks. Immunoglobulin G (IgG) can take up to 3 days and immunoglobulin A (IgA) can take up to 21 days, because of this delay it can be very difficult to determine a food intolerance. Testing for these types of intolerances is more expensive as a panel of many foods needs to be tested, but can be useful if elimination and challenge diets for one reason or another cannot be undertaken or in serious chronic immune diseases. Symptoms can include but not limited to anyone of the following:

• depression, anxiety
• gut issues (irritable bowel syndrome, inflammatory bowel disease, constipation, diarrhoea)
• migraines, headaches
• fluid retention
• behavioural problems
• skin conditions
• bloating
• bronchitis, asthma, persistent cough
• chronic fatigue syndrome, lethargy
• sleep disturbances
• stomach aches
• weight control
• autism (usually have higher IgG results to casein, protein found in milk, than others)
• fibromyalgia, body pain and aches
• runny nose

Interestingly an increased IgG to egg white, orange, wheat or rice can be a predictor to IgE issues to dust, cat, dog hair. IgG antibodies are found in all body fluids and therefore are very common, they fight bacteria and virus and are the only antibodies which can cross the placenta. They are common in both adults and children and some of the more commonly reactive foods include cows milk, eggs, beans, nuts, cereals. These reactions are exposure driven, so high consumption of one food may lead to a false positive and no consumption may show a false negative. IgG reactions can be reintroduced after a period of avoidance, this is determined on a case by case situation, but this is very important, as once digestion is improved IgG reactions improve. A result showing many or most foods being reactive requires much attention in improving gut function.

The Wrap Up!

REFERENCES

• Springer- Quercetin inhibits expression of inflammatory cytokines
• Europemc-Cardiac Toxicity
• BMJ-drug reactions of systemic antihistamines
• BMJ-HOW SAFE IS ON-LABEL DRUG USE IN PAEDIATRICS
• Science Direct-Antacid medication inhibits digestion
• Erasmas University-Pro-arrhythmic potential of oral antihistamines 
• Annual Reviews-Cardiac actions of antihistamines
• AJOCN-Histamine intolerance