En Español

Allergies and Sensitivities

Also indexed as:Sensitivities and Allergies, Chemical Allergies
Take action to control your allergies. Breathe easy by learning more about how to manage symptoms. According to research or other evidence, the following self-care steps may be helpful.
Allergies and Sensitivities: Main Image

About This Condition

Allergies are responses mounted by the immune system to a particular food, inhalant (airborne substance), or chemical. In popular terminology, the terms “allergies” and “sensitivities” are often used to mean the same thing, although many sensitivities are not true allergies. The term “sensitivity” is general and may include true allergies, reactions that do not affect the immune system (and therefore are not technically allergies), and reactions for which the cause has yet to be determined.

Some non-allergic types of sensitivity are called intolerances and may be caused by toxins, enzyme inadequacies, drug-like chemical reactions, psychological associations, and other mechanisms.1 Examples of well-understood intolerances are lactose intolerance and phenylketonuria. Environmental sensitivity or intolerance are terms sometimes used for reactions to chemicals found either indoors or outdoors in food, water, medications, cosmetics, perfumes, textiles, building materials, and plastics. Detecting allergies and other sensitivities and then eliminating or reducing exposure to the sources is often a time-consuming and challenging task that is difficult to undertake without the assistance of an expert.

Symptoms

Common symptoms may include itchy, watery eyes; sneezing; headache; fatigue; postnasal drip; runny, stuffy, or itchy nose; sore throat; dark circles under the eyes; an itchy feeling in the mouth or throat; abdominal pain; diarrhea; and the appearance of an itchy, red skin rash. Life-threatening allergic reactions—most commonly to peanuts, nuts, shellfish, and some drugs—are uncommon. When they do occur, initial symptoms may include trouble breathing and difficulty swallowing.

What conditions are related to allergies?

According to J. C. Breneman, M.D., author of the book Basics of Food Allergy,2 many health conditions are related to allergies and have been the subject of independent studies. Even so, any relationship between the condition and the allergy needs to be considered with the aid of a doctor. More information about the relationship between specific health conditions and allergies or other sensitivities can be found in the following articles:

The following conditions may also be related to allergies and other sensitivities:

Bed-wetting (Nocturnal enuresis)

If there is no medical cause for bed-wetting, allergies should be investigated. Several researchers have reported that allergies appear to be an important cause of bed-wetting.99, 100

Cyclic vomiting syndrome

Allergies to foods, especially cows’milk, may play a role in cyclic vomiting syndrome, a disorder characterized by repeated unpredictable, explosive and unexplained bouts of vomiting.101 This condition affects nearly 2% of school-aged children.102

Gastrointestinal symptoms

Vague gastrointestinal (GI) symptoms (such as abdominal pain, bloating, gas, and diarrhea) that are not caused by serious disease can sometimes be triggered by food sensitivities. In one double-blind trial, people with vague GI problems believed to be caused by dairy were given dairy to see how their bodies would react.103 These people were not lactose intolerant. Various indicators of immunity changed as a result of the dairy challenge, showing their bodies were reacting to the dairy in an abnormal way. However, the indicator of a true dairy allergy (milk-specific immunoglobulin E) was normal in most of these people. This study suggests that vague GI symptoms unrelated to serious disease can be caused by food sensitivities that reflect neither lactose intolerance nor true allergies.

IgA nephropathy (autoimmune kidney disease)

In a small, preliminary trial, people with IgA nephropathy consumed a hypoallergenic diet (rice, olive oil, turkey, rabbit, lamb, green vegetables, potatoes, pears, apples, salt, and water) for 14 to 23 weeks. Laboratory parameters for kidney function improved significantly, and all participants remained relapse-free while maintaining the diet.104

Multiple Food Protein Intolerance (MFPI) of infancy

Many infants who are intolerant to one food have been found to also be intolerant to several other food proteins, including soy formula and extensively hydrolyzed formula. This syndrome has recently been dubbed Multiple Food Protein Intolerance (MFPI) of infancy. As a group, these infants tend to have symptoms of severe colic, gastroesophageal reflux and esophagitis (inflammation of the esophagus due to irritation by stomach acids from repeated episodes of reflux), or atopic dermatitis (eczema). As many as 30% of infants may suffer from these symptoms, but it is not yet clear how many of them may be suffering from this syndrome.105

Multiple chemical sensitivity

Multiple chemical sensitivity, also known as idiopathic environmental intolerances, is a poorly understood and controversial chronic disorder in which a person may have a variety of recurring symptoms believed to be due to reactions to very small amounts of substances in the environment.106, 107, 108 Avoidance of these substances, though often difficult, has been reported to bring at least partial relief,109 and psychological counseling has also been reported to be helpful.110

Musculoskeletal pain (including back pain)

Ingestion of allergenic foods has been reported to produce a variety of musculoskeletal syndromes in susceptible people.111

Nephrotic syndrome

Several studies have found a link between nephrotic syndrome (a kidney disease) and allergies. In one study nephrotic syndrome patients responded when the allergens were removed from their diet;112 however, in another study patients did not respond.113

Leaky gut syndrome

Allergy to food has been associated with increased permeability, or “leakiness,” of the intestine.114, 115 Some alternative health practitioners believe that this increased permeability, sometimes referred to as the “leaky gut syndrome,” is an important treatable cause of food allergy. However, the reverse may also be possible. Allergic reactions in the intestine tend to cause temporary increases in permeability,116, 117 which would explain the apparent connection between the two. More research is needed to better understand the role of intestinal permeability in the development and treatment of food allergies.

Healthy Lifestyle Tips

People with inhalant allergies are often advised to reduce exposure to common household allergens like dust, mold, and animal dander, in the hope that this will reduce symptoms even if other, non-household allergens cannot be avoided.118 Strategies include removing carpets, frequent cleaning and vacuuming, using special air filters in the home heating system, choosing allergen-reducing bed and pillow coverings, and limiting household pets’ access to sleeping areas.

Holistic Options

Acupuncture may be helpful in the treatment of some types of allergy. Studies of mice treated with acupuncture provide evidence of an anti-allergic effect with results similar to treatment with corticosteroids (cortisone-like drugs).119, 120, 121 A preliminary trial found a significant decrease in allergy symptoms following acupuncture treatment. It was found that the decline in symptoms coincided with a decline in laboratory measures of allergy. Relief persisted for two months following the treatment.122 Other preliminary trials have also demonstrated positive results.123 One controlled trial reported a reduction in allergic complaints following acupuncture treatment, but the results were not statistically significant.124 In the future, controlled trials with larger numbers of subjects may help to determine conclusively whether allergies can be successfully treated with acupuncture therapy.

Provocation-neutralization is a controversial method of both allergy testing and treatment. Treatment consists of injecting minute dilutions of foods, inhalants, or (in some cases) chemicals into the lower layers of the skin. This approach is not the same as traditional desensitization injections given by medical allergy specialists. Preliminary125, 126 and double-blind127, 128 research suggests treatment of allergies by provocation-neutralization may be effective, though negative double-blind research also exists.129

Allergy treatment using extracts of allergens taken orally is another controversial method advocated by some alternative healthcare practitioners.130 Most131, 132, 133, 134 but not all double-blind trials135, 136 have found this approach effective for house dust allergy. Preliminary137 and double-blind138, 139, 140 trials have reported success using this method for other allergies as well.

Treatment of food allergy using very small but increasing daily doses of actual foods has been reported,141 and in one controlled trial142 12 of 14 patients successfully completed the program and could tolerate previously allergenic foods.

All desensitization programs require the guidance of a healthcare professional. While none of these approaches has been unequivocally proven, several show promise that people with allergies may be treatable by means other than simple avoidance of the offending food or inhalant substance.

What tests can detect allergies? Several tests or procedures are used by physicians to detect allergies. Most of these tests remain controversial.143 Some clinicians (cited below), however, believe some of these tests can be effective.

Scratch testing

This form of testing is one of the most widely used. A patient’s skin is scratched with a needle that contains a portion of the food, inhalant, or chemical that is being tested. After a period of time, the skin is examined for reactions. If there is a reaction, it is determined that an allergy exists. Although this test is accepted by most allergists, scratch testing is subject to a relatively high incidence of inaccurate results, some tests showing positive when the person is not truly allergic to the substance (false positive) and some tests showing negative when an allergy really exists (false negative).

RAST/MAST/PRIST/ELISA (and other tests that measure immunoglobulins)

The radioallergosorbent test (RAST) indirectly measures antibodies in the blood that react to specific foods. It is used by many physicians and has been shown to be a somewhat reliable indicator of allergies.144, 145 It does not, however, help diagnose non-allergic food sensitivities and is therefore associated with a high risk of false negative readings. In an attempt to avoid this problem, a variety of modifications have been made to tests related to RAST (such as MAST, PRIST, and ELISA). Some of these changes may have reduced the risk of false negative readings somewhat but are likely to have increased the risk of false positive readings. A number of conditions associated with food sensitivities, such as migraine headaches and irritable bowel syndrome, have shown remarkably poor correlation between RAST results and the actual sensitivities of patients.

Cytotoxic testing

The cytotoxic test views a patient’s serum under a microscope to see whether it is reacting to certain substances. The test is subject to numerous errors and is not generally considered to be reliable.146

Clinical ecology (provocation-neutralization; end-point titration)

This branch of medicine is considered very controversial. Testing is done using intra-dermal (under the skin) injections of minute dilutions of foods, inhalants or (in some cases) chemicals. Based on reactions, additional dilutions are used. This test not only determines whether an allergy exists but also operates on the theory that one dilution can trigger a reaction while another can neutralize a reaction. Preliminary research suggests this approach may have beneficial effects,147, 148 A similar method uses these dilutions under the tongue to test for allergies.149 Double-blind research has not found this method effective. 150

Elimination and reintroduction

The most reliable way to determine a food allergy is to have the patient eliminate a suspected food from the diet for a period of time and then reintroduce it later. Once a food is eliminated, the symptoms it may be causing either improve or resolve, typically after several days to three weeks. The body then becomes more sensitive to the food, so when the food is reintroduced, the symptom is more likely to recur. This tool shows with a high degree of certainty which foods are problem foods. The testing requires a great deal of patience and, as with all other forms of allergy testing, is best undertaken with the help of a physician who can monitor the diet.151 Reintroduction of an allergenic food has been reported to lead occasionally to dangerous reactions in some people with certain conditions, particularly asthma—another reason this approach should not be attempted without supervision.

Other tests

Bioelectric tests are controversial procedures that attempt to measure changes in electrical activity at acupuncture points when a potential allergen is brought into proximity. A preliminary study reported that the EAV (Electroacupuncture According to Voll) device, also called the Vega test, identified the same allergens as RAST testing in 70.5 percent of tests.152 Another preliminary study found the Vega test identified the same neutralization doses as clinical ecology testing (see above) in 66% of tests.153 More research is needed to better evaluate these testing techniques.

Copyright © 2025 TraceGains, Inc. All rights reserved.

Learn more about TraceGains, the company.

The information presented by TraceGains is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2025.