Food Allergy

Food Allergy


A food allergy occurs when the body’s immune system responds to otherwise benign proteins (allergens) as though they threatened the health and integrity of the system. In a classic reaction, the immune system attempts to counter the food allergens by stimulating IgE antibodies. When these antibodies react with the allergen, histamine and other chemicals (mediators) are released. This process then gives rise to such allergic symptoms as itching, swelling, hives, and breathing difficulties. While most food allergies are mild, in some cases, they can cause anaphylactic shock. Because this type of reaction can be life-threatening, food allergies must be taken seriously.

Approximately 5% of children younger than age 3 have food allergies. As many as two out of five Americans believe that they have allergies to certain foods. According to the National Institute of Allergy and Infectious diseases, fewer than 2%—about 4 million Americans—have true food allergies.

The majority of adverse reactions to food are caused by nonimmunologic mediated mechanisms. Also called food intolerance or food hypersensitivity, adverse food reactions can occur because a person lacks the enzymes needed for proper digestion, such as for the lactose in milk, or has a sensitivity to such common preservatives and additives as monosodium glutamate (MSG), sulfites, and gluten. Some adverse reactions are caused by food-borne microbial pathogens and toxins.


Foods that most commonly cause allergic reactions include peanuts, tree nuts, milk, eggs, soy, fish, shellfish, wheat, some fruits, seeds, and chocolate. Food allergies arise when a genetic sensitivity is coupled with environmental exposure.

Risk Factors

Family history of allergies, asthma, or atopic dermatitis

Personal history of asthma, atopic dermatitis, or other allergies

Signs and Symptoms

Patches of swelling (urticaria, angioedema), atopic dermatitis, hives

Swelling or itching lips, tongue, and mouth

Itching or tightness in the throat

Runny and itchy nose


Nausea, cramping, vomiting, flatulence, diarrhea

Respiratory distress

The following symptoms should be treated as a medical emergency.

Immediate and extreme facial swelling and itching

Breathing difficulties

Rapid increase in heart rate

Rapid drop in blood pressure

Tightening of the throat

Sudden hoarseness

Differential Diagnosis

Food intolerance or food poisoning

Seasonal or environmental allergies or asthma


Viral hepatitis

Parasitic infection

Urticarial vasculitis

Skin malignancy

Connective tissue disease

Physical Examination

Physical assessment includes noting characteristic symptoms, signs, and pattern of reaction, as well as a history of past exposures and reactions to related foods.

Laboratory Tests

The blood tests radioallergosorbent (RAST) and enzyme-linked immunosorbent assay (ELISA) are generally more useful in ruling out a food allergy than diagnosing one.


Blood tests reveal elevated levels of IgE antibodies or the presence of eosinophilia.


In rare cases of gastric inflammation, an upper GI series may be needed.

Other Diagnostic Procedures

Assess the likelihood of a more serious reaction through the examination, patient’s history, and description of reaction pattern to certain foods. Further tests may be needed to assess patient’s overall susceptibility to food and other allergies. Suggest that patient keep a food diary that tracks eating habits, medications, and adverse reactions.

Elimination trial, supervised by health care provider. See “Nutrition” section.

Skin tests that measure a person’s reactions to superficial contact with suspected allergens can determine or rule out a food allergy.

Challenge or provocative testing involves placing food extracts under the tongue or injecting them under the skin. However, this test tends to be expensive and unreliable. Provoking symptoms is not advised for patients who have experienced anaphylactic reactions to foods, insect stings, or medications.

Treatment Strategy

There is no cure for food allergies. Managing them usually means avoiding offending foods and treating symptoms when they occur. If the problem involves food intolerance, a registered dietitian may be helpful in guiding the patient so that reactions are minimized, thus avoiding unnecessary food restrictions.

Usually, once the food is eliminated from the diet, symptoms will abate. However, avoidance may not always be possible. For example, the substance may be present as an unspecified additive within another food or “hidden” in another form. Other factors such as the amount of the food, which parts of the food are used, or the way in which it is prepared can influence the systemic response. Therefore, treatment may be necessary to address occasional allergic symptoms.

Drug Therapies

Antihistamines—for mild itching, swelling, rash, runny nose, or headache; available both by prescription and over the counter in many cold, sinus, and allergy remedies. These include diphenhydramine (Benadryl), clemastine (Tavist), chlorpheniramine (Chlor-Trimeton), loratadine (Claritin), and astemizole (Hismanal). Possible side effects include drowsiness, irritability, dry mouth, and heart palpitations. Hismanal when used with erythromycin, clarithromycin, and antifungal medications such as Nizoral and Sporanox can cause irregular heartbeat, fainting, dizziness, and, rarely, cardiac arrest and death.

Antispasmodics—such as hyoscyamine (Levsin, Anaspaz) for diarrhea, nausea, abdominal bloating, and cramping.

Adrenaline (epinephrine injection)—for anaphylactic shock.

Complementary and Integrative Therapies

The key to treatment of food allergy is complete avoidance of allergens for four to six months. Reducing inflammation, minimizing hypersensitivity reactions, and restoring the integrity of the digestive tract are ways in which alternative therapies may help resolve food allergies.

Hypersensitivity reactions may be associated with stress and anxiety. Mind-body techniques such as meditation, tai chi, yoga, and stress management may help normalize immune function.


Note: Lower doses are for children.

Eliminate all food allergens from the diet. The most common allergenic foods are dairy, soy, citrus, peanuts, wheat, fish, eggs, corn, chocolate, and tomatoes.

An elimination/challenge trial may be helpful in uncovering sensitivities. Remove suspected allergens from the diet for two weeks. Re-introduce foods at the rate of one food every three days. Watch for reactions which may include gastrointestinal upset, mood changes, headaches, and exacerbation of symptoms. Do not perform a challenge with peanuts if there is history of anaphylaxis.

A rotation diet, in which the same food is not eaten more than once every four days, may be helpful in minimizing food allergies.

Reduce pro-inflammatory foods in the diet including saturated fats (meats, especially poultry, and dairy), refined foods, and sugar. For those with sensitivities to antibiotics it is essential to eat only organic meats to avoid antibiotic residues.

Increase intake of fresh vegetables, whole grains, and essential fatty acids (cold-water fish, nuts, and seeds).

Eat more antioxidant rich foods (such as green leafy vegetables) and fruits (such as blueberries, pomegranates, and cherries).

Flaxseed, borage, or evening primrose oil (1,000 to 1,500 mg one to two times/day) are anti-inflammatory. Children should be supplemented with cod liver oil (½ to 1 tsp./day).

Use healthy cooking oils, such as olive oil.

A multivitamin daily, containing the antioxidant vitamins A, C, E, the B complex vitamins, and trace minerals such as magnesium, calcium, zinc, and selenium.

Omega-3 fatty acids, such as fish oil, 1 – 2 capsules or 1 tablespoonfuls oil, 1 – 3 times daily, to help decrease inflammation and help with immunity. Cold water fish, such as salmon or halibut, are good sources, but are not substitutes for supplementation. Patients on blood thinning medications or with bleeding disorders should take fish oil only under the supervision of a doctor.

Zinc (10 to 30 mg/day) and beta-carotene (25,000 to 50,000 IU/day) support immune function and encourage healing of mucosal tissues.

Vitamin C (250 to 1,000 mg bid to qid) inhibits histamine release. Vitamin C from rose hips or palmitate is citrus-free and hypoallergenic.

B-complex vitamins (25 to 100 mg/day) help to reduce the effects of stress and normalize immune function.

Selenium (50 to 200 mcg/day) helps to regulate fatty acid metabolism and is a cofactor in liver detoxification.

Bromelain (100 to 250 mg between meals) is a proteolytic enzyme that decreases inflammation.

Pancreatin (8X USP) one to two tablets with meals to enhance digestion.

Pro-flora supplements (one to three capsules/day) can help to normalize bowel flora.

L-glutamine, 500 – 1,000 mg 3 times daily, for support of gastrointestinal health and immunity.

Probiotic supplement (containing Lactobacillus acidophilus), 5 – 10 billion CFUs (colony forming units) a day, when needed for maintenance of gastrointestinal and immune health. Some products may require refrigeration — check labels carefully. Â

Coenzyme Q10, 100 – 200 mg per day, for antioxidant and immune activity.


Herbs are generally a safe way to strengthen and tone the body’s systems. As with any therapy, it is important to ascertain a diagnosis before pursuing treatment. Herbs may be used as dried extracts (capsules, powders, teas), glycerites (glycerine extracts), or tinctures (alcohol extracts). Unless otherwise indicated, teas should be made with 1 tsp. herb per cup of hot water. Steep covered 5 to 10 minutes for leaf or flowers, and 10 to 20 minutes for roots. Drink 2 to 4 cups/day. Tinctures may be used singly or in combination as noted.

Green tea (Camelia sinensis) standardized extract, 250 – 500 mg daily, for inflammation, and for antioxidant and immune effects. Use caffeine free products. You may also prepare teas from the leaf of this herb.

Milk thistle (Silybum marianum) standardized seed extract, 80 – 160 mg 2 – 3 times daily, for detoxification support. People allergic to ragweed and related plants may also be sensitive to milk thistle. Because of its actions on the liver, milk thistle may react with certain medications that are processed by the liver.Â

Bromelain (Ananus comosus) standardized, 40 mg 3 times daily, for inflammation. Bromelain has anticoagulant effects. It should not be combined with other blood-thinning medications or used with people with bleeding disorders. It may interact with certain mediations, including some antibiotics. People with allergies to pineapple, wheat, celery, carrot, papain, fennel, pollens, and cypress may have cross-reactivity with bromelain.

Turmeric (Curcuma longa) standardized extract, 300 mg 3 times a day, for inflammation. Tumer has a powerful anticoagulant effect and should not be combined with other blood-thinning medications or used by people with bleeding disorders.

Cat’s claw (Uncaria tomentosa) standardized extract, 20 mg 3 times a day, for inflammation. Contraindicated in leukemia and auto-immune disorders. Can interact with many medications, including blood pressure medication.

Quercetin (100 to 250 mg tid before meals) minimizes reactions to food.

Rose hips (Rosa canina) tea is anti-inflammatory, high in hypoallergenic vitamin C, and healing to the digestive tract. Drink 3 to 4 cups/day, 4 oz. tid to qid for children. This is particularly effective for children.

Marshmallow root tea (Althea officinalis) may soothe and promote healing of gastrointestinal inflammation. Soak 1 heaping tbsp. of marshmallow root in 1 qt. of cold water overnight. Strain and drink throughout the day.

Dandelion (Taraxacum officinale), milk thistle (Silybum marianum), celandine (Chelidonium majus), and chicory (Cichorium intybus) stimulate liver function.

Soothing carminative herbs will enhance digestion and reduce spasm. Choose three or more of the following to make a tea to sip before meals. Chamomile (Matricaria recutita), peppermint (Mentha piperita), passionflower (Passiflora incarnata), meadowsweet (Filipendula ulmaria), fennel (Foeniculum vulgare), and catnip (Nepeta cataria).


An experienced homeopath should assess individual constitutional types and severity of disease to select the correct remedy and potency. Although very few studies have examined the effectiveness of specific homeopathic therapies, professional homeopaths may consider individualized remedies for the treatment of food allergy based on their knowledge and experience. Before prescribing a remedy, homeopaths take into account a person’s constitutional type — your physical, emotional, and intellectual makeup. An experienced homeopath assesses all of these factors when determining the most appropriate remedy for a particular individual.


Acupuncture may help restore normal immune function and reduce the hypersensitivity response.


Therapeutic massage may help reduce the effects of stress.

Patient Monitoring

A diet based on vegetables, fruits, and high-fiber foods and one that is also low in fat and refined sugar is considered best when addressing any type of allergy. Because there seems to be a connection between the inflammatory process and animal fat, it may help to reduce consumption of animal products.


Conservative introduction of solid foods as child is weaning may help prevent hypersensitivity conditions. If there is a strong family history of allergies or atopic conditions and/or if the child’s immunity has been compromised in infancy, delay the introduction of highly allergenic foods until one year or older.


Some research suggests a link between food allergies and celiac disease, arthritis, chronic infection, depression, anxiety, and chronic fatigue.


Most infants outgrow their sensitivity to food by 2 to 4 years. Adults with food allergies tend to retain them for years. While there is no cure for food allergies, prognosis for remaining symptom-free is excellent as long as offending foods are identified and avoided.


Nutritional support may safely relieve symptoms during pregnancy.


Berni C, Ruotolo S, Discepolo V, Troncone R. The diagnosis of food allergy in children. Curr Opin Pediatr. 2008;20(5):584-9.

Blumchen K, Ulbricht H, Staden U, Dobberstein K, Beschorner J, de Oliveira LC, Shreffler WG, Sampson HA, Niggemann B, Wahn U, Beyer K. Oral peanut immunotherapy in children with peanut anaphylaxis. J Allergy Clin Immunol. 2010;126(1):83-91.e1.Â

Calvani M, Giorgio V, Miceli Sopo S. Specific oral tolerance induction for food. A systematic review. Eur Ann Allergy Clin Immunol. 2010;42(1):11-9.

Chandra RK. Food allergy. Indian J Pediatr. 2002;69(3):251-255.

DesRoches A, Infante-Rivard C, Paradis L, Paradis J, Haddad E. Peanut allergy: is maternal transmission of antigens during pregnancy and breastfeeding a risk factor? J Investig Allergol Clin Immunol. 2010;20(4):289-94.

Finkelman FD. Peanut allergy and anaphylaxis. [Review]. Curr Opin Immunol. 2010;22(6):783-8.Â

Fisher HR, du Toit G, Lack G. Specific oral tolerance induction in food allergic children: is oral desensitisation more effective than allergen avoidance?: a meta-analysis of published RCTs. [Review]. Arch Dis Child. 2011;96(3):259-64.Â

Friedrich MJ. A bit of culture for children: probiotics may improve health and fight disease. JAMA. 2000;284(11):1365-1366.

Heine RG, Tang ML. Dietary approaches to the prevention of food allergy. Curr Opin Clin Nutr Metab Care. 2008;11(3):320-8.

Hill DJ, Roy N, Heine RG, et al. Effect of a low-allergen maternal diet on colic among breastfed infants: a randomized, controlled trial. Pediatrics. 2005;116(5):e709-15.

Host A, Halken S. Primary prevention of food allergy in infants who are at risk. Curr Opin Allergy Clin Immunol. 2005;5(3):255-9.

Hourihane JO. Recent advances in peanut allergy. Curr Opin allergy Clin Immunol. 2002;2(3):227-231.

Itoh N, Itagaki Y, Kurihara K. Rush specific oral tolerance induction in school-age children with severe egg allergy: one year follow up. Allergol Int. 2010;59(1):43-51.Â

Kalliomaki M, Salminen S, Arvilommi H, Kero P, Koskinen P, Isolauri E. Probiotics in primary prevention of atopic disease: a randomized placebo controlled trial. Lancet. 2001;357(9262):1076-1079.

Knight AK, Bahna SL. Diagnosis of food allergy. Pediatr Ann. 2006;35(10):709-14.

Kukkonen K, Savilahti E, Haahtela T, et al. Probiotics and prebiotic galacto-oligosaccharides in the prevention of allergic diseases: a randomized, double-blind, placebo-controlled trial. J Allergy Clin Immunol. 2007;119(1):192-8.

Li XM. Treatment of asthma and food allergy with herbal interventions from traditional chinese medicine. Mt Sinai J Med. 2011;78(5):697-716. doi: 10.1002/msj.20294.

Lowe AJ, Hosking CS, Bennett CM, Allen KJ, Axelrad C, Carlin JB, Abramson MJ, Dharmage SC, Hill DJ. Effect of a partially hydrolyzed whey infant formula at weaning on risk of allergic disease in high-risk children: a randomized controlled trial. J Allergy Clin Immunol. 2011;128(2):360-365.e4.Â

Mahoney EJ, Veling MC, Mims JW. Food allergy in adults and children. [Review]. Otolaryngol Clin North Am. 2011;44(3):815-33, xii.

Martorell A, De la Hoz B, Ibáñez MD, Bone J, Terrados MS, Michavila A, Plaza AM, Alonso E, Garde J, Nevot S, Echeverria L, Santana C, Cerdá JC, Escudero C, Guallar I, Piquer M, Zapatero L, Ferré L, Bracamonte T, Muriel A, Martínez MI, Félix R. Oral desensitization as a useful treatment in 2-year-old children with cow’s milk allergy. Clin Exp Allergy. 2011 Sep;41(9):1297-304. doi: 10.1111/j.1365-2222.2011.03749.x.

Noh G, Ahn HS, Cho NY, Lee S, Oh JW. The clinical significance of food specific IgE/IgG4 in food specific atopic dermatitis. Pediatr Allergy Immunol. 2007;18(1):63-70.

Nowak-Wegrzyn A, Muraro A. Food allergy therapy: is a cure within reach? [Review]. Pediatr Clin North Am. 2011;58(2):511-30, xii.Â

Nowak-Wegrzyn A, Sampson HA. Future therapies for food allergies. [Review]. J Allergy Clin Immunol. 2011;127(3):558-73; quiz 574-5.Â

Osborn D, Sinn J. Probiotics in infants for prevention of allergic disease and food hypersensitivity. Cochrane Database Syst Rev. 2007;4:CD006475.

Otsu K, Fleischer DM. Therapeutics in food allergy: The current state of the art. Curr Allergy Asthma Rep. 2011. [Epub ahead of print].

Ozol D, Mete E. Asthma and food allergy. Curr Opin Pulm Med. 2008;14(1):9-12.

Patil SP, Napihadkar PV, Bapat MM. Chickpea: a major food allergen in the Indian subcontinent and its clinical and immunochemical correlation. Ann Allergy Asthma Immunol. 2001;87(2):140-145.

Ring J, Mohrenschlager M. Allergy to peanut oil – clinically relevant? J Eur Acad Dermatol Venereol. 2007 Apr;21(4):452-5.

Sampson HA. Clinical practice. Peanut allergy. N Engl J Med. 2002;346(17):1294-1299.

Sears MR, Greene JM, Willan AR, et al. Long-term relation between breastfeeding and development of atopy and asthma in children and young adults: a longitudinal study. Lancet. 2002;360:901-907.

Seppo L, Korpela R, Lonnerdal B, et al. A follow-up study of nutrient intake, nutritional status, and growth in infants with cow milk allergy fed either a soy formula or an extensively hydrolyzed whey formula. Am J Clin Nutr. 2005;82(1):140-5.

Sicherer SH. Food allergy. Mt Sinai J Med. 2011;78(5):683-96. doi: 10.1002/msj.20292.Â

Sicherer SH, Wood RA, Stablein D, Lindblad R, Burks AW, Liu AH, Jones SM, Fleischer DM, Leung DY, Sampson HA. Maternal consumption of peanut during pregnancy is associated with peanut sensitization in atopic infants. J Allergy Clin Immunol. 2010;126(6):1191-7.

Smith K. Are Food Allergies on the Rise, or Is It Misdiagnosis? Journal of the American Dietetic Assoc. 2009;109(11).

Staden U, Rolinck-Werninghaus C, Brewe F, Wahn U, Niggemann B, Beyer K. Specific oral tolerance induction in food allergy in children: efficacy and clinical patterns of reaction. Allergy. 2007;62(11):1261-1269.

Vadas P, Wai Y, Burks W, Perelman B. Detection of peanut allergens in breast milk of lactating women. JAMA. 2001;285(13):1746-1748.

Vlieg-Boerstra BJ, van der Heide S, Bijleveld CM, et al. Placebo reactions in double-blind, placebo-controlled food challenges in children. Allergy. 2007;62(8):905-12.

Wang J, Patil SP, Yang N, Ko J, Lee J, Noone S, Sampson HA, Li XM. Safety, tolerability, and immunologic effects of a food allergy herbal formula in food allergic individuals: a randomized, double-blinded, placebo-controlled, dose escalation, phase 1 study. Ann Allergy Asthma Immunol. 2010;105(1):75-84.

American College of Allergy, Asthma and Immunology. Accessed at on January 1, 1999.

Carey CF, Lee HH, Woeltje KF, eds. The Washington Manual of Medical Therapeutics. 29th ed. New York, NY: Lippincott-Raven; 1998:216-217, 223-225.

Dambro MD, ed. Griffith’s 5 Minute Clinical Consult. Baltimore, Md: Williams & Wilkins; 1998:400-401.

Fauci AS, Braunwald E, Isselbacher KJ, et al., eds. Harrison’s Principles of Internal Medicine. 14th ed. St. Louis, Mo: McGraw-Hill; 1997.

The Food Allergy Network. Accessed at on January 1, 1999.

Klag MJ, ed. Johns Hopkins Family Health Book. Harper Resource; 1998.

Murray MT. Encyclopedia of Nutritional Supplements. Rocklin, Calif: Prima Health;1996:448-449.

Murray MT, Pizzorno JE. Encyclopedia of Natural Medicine. 2nd ed. Rocklin, Calif: Prima Publishing; 1998:321, 464-475.

National Institute of Allergy and Infectious Diseases. National Institute of Health. Accessed at on January 1, 1999.

Sampson HA. Food allergy. JAMA. 1997; 278:1888-1894.

Werbach M. Nutritional Influences on Illness. New Canaan, Conn: Keats Publishing Inc; 1987:23-28.