Pollen-food syndrome

Patents allergic to certain airborne pollens can display adverse reactions on the ingestion of plant-derived foods as a result of IgE-cross –reactive structures shared by pollen and food allergen sources.

This clinical entity is known as the pollen-food syndrome. Pollen-food syndrome or oral allergy syndrome is a term describing associations between inhalant pollen allergies and allergic manifestations on ingestion of particular fruits, vegetables and spices.

It results from a primary sensitization to labile pollen allergens such as Bet v 1 or profilin, and the resulting phenotype is mainly mild, consisting of local oropharyngeal reactions.

Sensitization to the pollen occurs through the respiratory system. Patients with pollen-food syndrome generally tolerate cooked forms of the fruit or vegetable to which they are allergic, and allergists often recommended that they cook reactive fruits and vegetables before ingesting them.

Symptoms of pollen-food syndrome are coffined almost exclusively to the oropharynx and include itchy mouth, scratchy throat or swelling of the lips, mouth, uvula, tongue, and throat tightness.

Itchy ears are sometimes reported. Rarely, other target organs are involved.
Pollen-food syndrome

Food idiosyncrasies: Sulfite sensitivities

One of the common food idiosyncrasies is sulfite sensitivity. Sulfites are preservatives used most commonly in wine and dried fruits and vegetables.

Sulfite is used as food additives in a variety of foods. Sulfites exist in several forms: sulfur dioxide, sodium metabisulfite, potassium, metabisulfite, sodium bisulfite, potassium bisulfite and sodium sulfite.

Sulfite sensitivity is an idiosyncratic reaction of undefined mechanism associated with the ingestion of sulfites in foods and medications. The symptoms associated with idiosyncratic reactions can be form trivial to life threatening.

People who are sensitive to sulfite can have such severe reactions that range from shortness of breath to fatal shock.
sym
Very small amounts of sulfites can cause anaphylactic shock and bring in an asthma attack in sensitive people. The FDA requires that processed foods containing sulfites list sulfites in the ingredient label.
Food idiosyncrasies: Sulfite sensitivities

Symptoms of food allergy

Allergies have become an epidemic of the 21st century. Substances that cause allergy reactions are called allergens. 

A symptomatic allergy will exhibit different symptoms depending on the location of the reaction.

Food sensitivity can affect virtually any organ system in the body. In digestive tract, the allergy may cause nausea or vomiting; in the skin, it may cause rashes and in the nasal passages and lungs, it may cause inflammation or asthma.

Because food is ingested into the gastrointestinal tract, GI symptoms should be the first consideration in deciding whether food allergy could be a significant problem.

Gastrointestinal symptoms in food allergy are often chronic or acute vomiting, diarrhea and colic. Colic appears to be a common symptom, but nearly always in combination with other symptoms.

People who have life-threatening reactions usually have asthma and frequently have a history of atopy, including atopic dermatitis and food allergy as young children.

Symptoms may develop within minutes to a few hours after ingestion of the food, and in life-threatening cases, symptoms include sever bronchospasm.

In adults, food allergy triggers most often the oral allergy syndrome, which occurs almost exclusively and an immediate, IgE-mediated reaction.

 The short time interval between allergen exposure and onset of symptoms such as itching of the buccal mucosa, and the classical set of food like apples and other pome fruits that triggers the oral allergy syndrome make diagnosis usually easy.
Symptoms of food allergy

What is egg intolerance?

Eggs and egg products are listed among the ingredients causing allergies or intolerance.

Egg intolerance is defined as egg-white-induced, small intestinal mucosa damage that is reversed by an egg-free-diet and reoccurs on challenge.

It is an abnormal physiologic response to ovalbumin in genetically predisposed individuals.

Although egg intolerance has often been associated with children, it can arise at any age.

The reaction includes metabolic, toxic and inflammatory response to ovalbumin.

Egg intolerance can produce eczema and a rash. Sufferers need to avoid all eggs and egg products.
What is egg intolerance?

Food intolerances

Food intolerances can develop toward any naturally occurring or artificial food or food ingredient that ingested. Food intolerances affect the lives of virtually everyone at some point. People often may have an unpleasant reaction to something they ate and wonder if they have a food allergy.

Food intolerances produce some of the sane reactions as food allergies, but the reactions develop by different mechanisms.

When a particular food item causes irritation in different systems of the body, such as the gastrointestinal, skin, urogenital, musculoskeletal, neurological or respiratory system, without the presence of an immune reaction, it is defined as food intolerance. They are due to a missing enzyme or other cause.

Common intolerances have been observed to dairy, carbohydrate, gluten, yeast, dyes, flavor enhancers and preservatives.

True food intolerances produce predictable reactions. Problems such as headache, diarrhea, swelling or stomach pain will occur every time a person consumes a difficult amount of the suspected food.

Intolerance symptoms tend to be milder than allergy symptoms and include nausea, stomach pain, and diarrhea, gas, cramps, bloating, vomiting, headaches, heartburn and irritability.

Lactose intolerance is one example of a food intolerance. Lactose intolerances affects between 30 and 50 million Americans, 75% of African Americans and over 90% of Asian Americans.

Celiac disease, a sensitivity to gluten, a wheat protein, affects about 20% of Americans.
Food intolerances

Food allergy symptoms

What is food allergy? A food allergy is an immune system response that creates antibodies to attack substances in a food that body immune system identifies as harmful.

Having sudden allergic symptoms within an hour or two of eating a food should raise suspicions of food allergy. Symptoms of food allergies including:

Respiratory symptoms
*Rhinitis – copious watery discharged from mucous membrane of nose
*Asthma – pulmonary distress or breathing difficulty

Cutaneous symptoms
*Urticaria – hives. It is one of the most common symptoms of anaphylaxis.
*When foods cause a constant inflammation in the body, the person may have chronic rashes of allergic eczema, also called atopic dermatitis.

Gastrointestinal symptoms
*They may be gut symptoms of vomiting, pain or diarrhea. Chronic stomachache can be the sign of a food allergy.
*Diarrhea – watery stools, usually with cramping
*Itching in the mouth
*Swelling of the tongue

Other symptoms
*Angio-edema/edema – swelling, often widespread and severe especially when affecting the oral / laryngeal area. It is one of the common symptoms of anaphylaxis.
*Anaphylactic shock –severe generalized shock – can result in death headache. Anaphylaxis is a severe allergic retain that is rapid in onset and can be fatal.
*Weight loss and poor growth of children
Food allergy symptoms

Food allergy

A food allergy is an immune system response that creates antibodies to attack substances in a food that human immune system recognized as ‘foreign’.

In the process, the reaction releases huge stores of chemical substances, including histamines, which cause symptoms ranging from a mild case of hives to a potentially life-threatening system shutdown.

People may feel itchy, break out in hives, or get stomach cramps. Some vomit and have diarrhea.

Food allergies affect different people in different ways. Nevertheless, most people with food allergies lead full and happy lives, they enjoy most foods.

People whose parents or their close relatives have allergic disease have a greater tendency than others to develop an allergy at some time in their lives. The most common allergic diseases are asthma,, eczema and hav fever.

When the term ‘allergy’ was first coined, it meant an adverse reaction to any substance that does not bother most people.

Then, in the 1920’s it was discovered that a type of antibody called ‘Reagin’ or IgE was involved in many allergic reactions especially those to inhabitants. So conventional medicine defined allergy as an IgE mediated response.

The number of people affected by allergy has increase dramatically since the early 970s, particularly in developed countries and it continue to increase.
Food allergy

Histamine Poisoning

Allergy like food intoxication is an adverse reaction to a food or food component occurring as result of the ingestion of chemical mediators of allergic disease.

Unusual diets can sometimes result in intoxication from chemicals that would normally be considered safe and desirable.

The only example of this type of reaction is histamine poisoning, also known as ‘scombroid fish poisoning,’ which is commonly associated with consumption of spoiled tuna, mackerel, mahi-mahi and other fish.

Histamine also been reported in connection with non-fish fermented food like cheeses and sauerkraut.

Following the ingestion of food containing high level of histamine, occurs with variety of symptoms. The primary symptoms are cutaneous – rash, urticaria, oedema, localized inflammation, gastro-intestinal – nausea, vomiting, diarrhea, hemodynamic – hypotension and neurological – headache, tingling, burning, itching.

Histamine production in foods is by the decarboxylation of histidine though a reaction catalyzed by the enzyme histidine decarboxylase.

Histamine poisoning is an intoxication, so the incubation period is rather short, ranging from several minutes to a few hours after ingestion of the contaminated fish.
Histamine Poisoning

Hypersensitivities Mechanisms

Hypersensitivities Mechanisms
Adverse reactions to food additives are caused by several mechanisms.

Food additives are ingested irregularly and in small doses. Additives are usually low by molecular weight chemicals, unlike many high molecular weight proteins which are potent allergens.

There is very little evidence of an immunological basis in reactions caused by food additives.

Adverse effects due to a various pharmacological or other mechanisms are much more common.

Many authors avoid the use of the terms allergy and atopy in connection with food additive reactions and prefer hypersensitivity or tolerance instead.

Terms such as false allergies, allergomimetic, reactions, or pseudoallergy have been suggested.

All these titles emphasize the nonspecific, nonimmunological nature of these reactions.

It has been observed in several studies that there is a dose response relationship with these reactions. A small amount of the agent is harmless, but a larger amount causes symptoms.

This better suits the concept of intolerance than immunologic sensitization.

Many patient suffering from food additives reactions have an atopic constitution and symptoms such as eczema and asthma.

Atopic subjects are more sensitive to numerous irritating environmental factors, including food additives, than the nonatopic population.

Atopic subjects have a particular tendency to release histamine after certain foods and additives that posses a histamine releasing action.

There appear to be more reactions caused by additives in adults than in children. The reason is obscure, but cumulative or slow development of intolerance may occur.

On the other hand, adults often have psychosomatic symptoms and are influenced by television programs and articles in journal and newspapers dealing with the adverse effects of food additives.
Hypersensitivities Mechanisms