Food Allergies

Laurie A. Higgins, RD

Food allergy can be defined as an "immunologie reaction resulting from the ingestion of a food or a food additive" as opposed to the more general term "food intolerance," which includes any abnormal response to a food or food additive.1 It has been estimated that 6 to of all children are affected by food allergies.Allergies may occur after a small amount of the allergen is ingested and are unrelated to any physiologic effect of the food, food additive, or cross-contaminant.2 The most common allergies encountered during infancy and childhood are to cow's milk protein (CMP), soy protein, fish. eggs, and cereals. Other foods children may be allergic to include berries, nuts, peanuts, and chocolate.4

There are four types of hypersensitivity reactions that may occur alone or in combination to cause allergic responses (Table 25-1). Clinical symptoms may be gastrointestinal. respiratory, dermatologie, or systemic in nature (Table 25-2).5 The "gold standard" for the diagnosis of food allergies is a double-blind, placebo-controlled food challenge. The cessation of symptoms after removal of the offending food(s) and their reappearance after its reintroduction is also a common test.'1 In addition, several clinical and laboratory tests exist to help in the diagnosis of food allergies (Table 25-3).

Formula-fed infants have a higher incidence of allergic symptoms than do breastfed infants. likely due to their earlier exposure to cow's milk protein. Since foreign antigens can be expressed in breastmilk, however, breastfed infants

Table 25-1. Four Types of Food Sensitivity Reactions

Type I: IgE, immediate (anaphylactic) hypersensitivity

Type II: Antibody-dependent cytotoxic hypersensitivity

Type III: IgG, immune complex-mediated hypersensitivity

Type IV: Cell-mediated hypersensitivity, T cells may still suffer from food allergies.7 Vomiting, diarrhea, and occult or frank blood in the stool due to food allergy is often referred to as allergic colitis.- The rectum and colon

Table 25-2. Food Allergy Symptoms

Gastrointestinal

Abdominal pain, bloating

Diarrhea, malabsorption, failure to thrive

Gastrointestinal bleeding

Nausea

Vomiting

Constipation

Skin

Eczema/atopic dermatitis Urticaria, angioedema, lip swelling Itching, rash

Respiratory Asthma Chronic cough Rhinitis/rhinorrhea Wheezing

Systemic/general Anaphylaxis

Other

Headache Behavioral changes

Adapted from Stern M. Allergic enteropathy. In. Walker WA, Durie PR.

Hamilton JR, et al. Pediatric gastrointestinal disease. 2nd ed. St. Louis:

Table 25-3. Common Laboratory Tests for Food Allergies

Laboratory Test

Procedure

Comments

Skin test (prick test)

A small amount ot the allergen is introduced to the skin; a wheal greater than 3 mm is usually interpreted as positive

Confirms sensitivity to the antigen but does not confirm diagnosis; positive test in children younger than the age of 1 year is likely to be significant A positive skin test to some foods may persist when clinical symptoms are no longer present

Radioactive immunosorbent test (RAST)

IgE antibodies to specific foods

IgE-mediated forms of food allergy only; may be substituted for skin test when there is a suspicion for anaphylaxis; poor correlation with oral challenge

Serum IgE

Blood test

Wide range of normal values; nonspecific and insensitive

Small bowel biopsy

Endoscopy

Nonspecific histopathology with patchy distribution

are inflamed due to immune-mediated responses to ingested proteins. Cow's milk protein is most often responsible for allergic colitis. Changing the infant's formula or removing the suspected antigens from the mother's diet will usually result in a decrease in bleeding within 72 hours: complete resolution, however, can lake up to 4 to 6 weeks.- Bottle-fed infants with allergic colitis should be treated with formula containing an extensively hydrolyzed protein since 10 to 50V< of infants with cow's milk protein allergy will also have an allergy to soy protein.5-7,g A small number of infants who may not respond to the extensively hydroly/.ed formula could benefit from an amino acid-based formula.1' If the infant is breastfed, the mother should eliminate all milk and soy proteins from her diet. If the symptoms of colitis resolve, soy protein can often be reintroduced slowly, with the child followed for signs of intolerance. In some cases, further maternal diet restrictions may be necessary. Other foods that have been associated with allergic colitis are wheat, eggs, corn. fish, seafood, and nuts.10 Care must be taken to avoid over-resiriction of the maternal diet since nursing mothers require 300 to 500 more calories and 15 to 20 g more protein per day than usual.

Many pediatric patients will outgrow their food allergies by the age of 3 to 5 years, with the exception of allergies to peanuts, fish, shellfish, and nuts.1 Reintroduction of foods can be done in either an open or a blinded format. The type of challenge should be determined by the physician and depends on the age of the child and the symptoms of the allergic presentation. In an open challenge, the patient is given a small amount of the food protein and followed for tolerance. In a double blind, placebo-controlled food challenge, the patient and caretaker are unaware of when the patient is receiving the suspected antigen. The challenge is usually done in a controlled environment so that the child can be observ ed closely and treated if adverse reactions occur Intravenous access should be secured before the challenge if severe symptoms are possible. The suspected antigen is in the form of a flour or the food itself ground into a powder. The placebo should consist of a powder of similar appearance and be mixed with a neutral food. The patient is given either the suspected antigen or placebo in an alternating and random order. The patient is observed and given a serving every 20 to 30 minutes, with the amount of food increasing until a total of 8 to 10 g dry or 60 to 100 g of w et food protein is ingested." If the patient does not react, then the double-blind challenge is followed by an open challenge to ensure that the allergy is no longer present.

Single food allergies, with the exception of milk, do not usually propose a nutritional risk for most children. Certain combinations of two or more food allergies, how ever. can make it difficult for the patient to consume a diet adequate in all macro- and micronutrients. This can be a particular concern in pediatrics since food variety can sometimes be limiting. Evaluation by a registered dietitian can provide the appropriate information, education, and suggestions for nutrient supplementation when a patient is placed on a restricted diet due to food allergy.

Examples of Restricted Diets*

Corn-Free Diet

The corn-free diet is a modification of the normal diet, with the following ingredients eliminated: corn, cornstarch. corn syrup, corn oil. corn sweeteners, maize, and popcorn. The following ingredients may also contain corn

"The following diets have been reproduced with the written permission of Children's Hospital. Boston (MA).

and should also be eliminated: hydrolyzed plant protein (HPP), hydrolyzed vegetable protein (HVP). starch (usually is cornstarch but can be wheat or other vegetables, which need not be eliminated).

Egg-Free Diet

The egg free diet is a modification of the normal diet, with the following ingredients eliminated: albumin (protein part of the egg), eggs, egg white, egg yolk, dried egg. egg powder, egg solids, some egg substitutes (which contained eggs), eggnog. globulin (could be egg protein), livetin. lysozyme (used in Europe), mayonnaise (made with egg whites and oil), meringue (made with egg whites and sugar), ovalbumin (principle protein in eggs), ovomucin, ovomucoid or ovovitellin (synonyms for egg protein), and Simplesse (fat substitute made from either egg or milk protein).

The follow ing are also potential sources of egg protein:

• Egg white or albumin contains most of the protein but the yolk should also be avoided.

• Many baked products that have a yellow color or shiny glaze are made w ith eggs/or egg whites.

• Egg whites are often used as a clarifying agent in broths or soups. Always check w ith the chef when dining out.

• Measles, mumps, and rubella vaccine includes egg protein. ■ Influenza vaccines are grown on egg embryos and could contain trace amounts of egg protein.

• Intravenous lipids use egg proteins as an emulsifier.

Tips for Egg-Free Cooking. There are a number of eggs substitutes that can be used in cooking. The following suggestions governing their use may be helpful:

• Use an egg substitute such as Jolly Joan, Golden Harvest, or Ener-G Foods egg replacer. Other brands such as Egg Beaters may have egg whites in them.

• Mashed bananas and apricot puree add flavor and act as both a binder and a thickener in place of egg in quick breads, cakes, cookies, or other sweets.

• Use 2 tbsp of pureed fruit for each egg in recipe. Also. 2 tbsp of pureed vegetables can replace an egg in soups, sauces, and other dishes.

• To bind or thicken fruit desserts, use I tsp of dry, unfavored gelatin mixed with 2 tbsp of liquid to replace one egg-

• Because baked goods without eggs crumble easily, use smaller pans. For example, make cupcakes instead of a cake, or muffins instead of bread. Xanthan gum is excellent for holding baked goods together. Use 1 tsp per recipe. To help leaven baked goods, add an extra 1/2 tsp egg-free baking powder for each egg called for in a recipe, with an additional egg substitute to bind or thicken.

• For thickening cream dishes and sauces, add extra flour, cornstarch, or xanthan gum.

• To enhance the flavor of egg-free cookies or cake, add extra ingredients such as raisins, nuts, coconuts, seeds, or spices.

In egg-free baked goods, the following egg substitutes may be used:*

• Tahini (ground sesame seeds): 2 tbsp to replace each egg

• Any nut butter: 2 tbsp to replace each egg

• Oat flour: 2 tbsp plus 1 tbsp water to replace each egg

• 1 tsp baking powder, 1 tbsp liquid, and 1 tbsp vinegar to replace each egg

• 1 tsp yeast dissolved in 1/4 cup warm water to replace each egg

• 11/2 tbsp water. 11/2 tbsp vegetable oil. and 1 tsp baking powder to replace each egg

'Adapted from Yoder HR. Allergy-free cooking. Addison-Wesley Publishing Co.; 1987.

Milk-Free Diet

The milk-free diet is a modification of a normal diet with the following ingredients eliminated: artificial butter flavor. butter, butter fat. buttermilk, casein (milk protein), caseinates (ammonium, calcium, magnesium, potassium, sodium), cheese, cottage cheese, curds, cream, custard, pudding, ghee (clarified butter). Half and Half, hydrolysales (casein, milk protein, protein, whey, whey protein), lactoglobulin. lactose, milk (derivative, protein, solids, malted, condensed, evaporated, dry, whole, low fat, nonfat. skim), nondairy creamer (check for casein), nougat, rennet (curdled milk), sour cream, sour cream solids, whey-milk protein (delactosed. demineralized. protein concentrate). and yogurt.

The following foods or ingredients may indicate the presence of milk or milk proteins: brown sugar flavoring, caramel flavoring, chocolate, high protein flour (protein source could be skim milk powder), margarine (may contain whey), natural flavoring, and Siniplesse (could be made from eggs or milk protein).

The following are potential sources of milk or milk proteins:

• Parve or pareve are words that indicate that the product is milk and meat free under Jewish law. The Food Allergy Network "no longer recommends relying on parve-labeled products for milk-free diets." since small amounts of milk may still be present.

• Product labels that include "Kd" or "Uo" indicate the presence of milk. The ingredient list does not always list the milk source. Some labels are now labeled "Kdh," indicating that the product is kosher but made on dairy equipment.

• Medication: certain vitamin and mineral supplements as well as some prescribed and over-the-counter drugs contain lactose as a tiller.

• Delicatessen meats often contain whey/casein in the brines surrounding the meat in prepackaged products. Crosscontamination from other meats/cheese products can also occur on slicing.

Nutritional Adequacy. If the patient is taking a fortified milk substitute (eg. soy or rice milk), a supplement may be unnecessary. If a fortified milk substitute is not consumed, the diet may be deficient in calcium, phosphorus, and vitamin D. Supplementation with these nutrients is then recommended (see Chapter 5. Nutritional Requirements: Dietary Reference Intakes and Chapter 13. Vitamin and Mineral Supplements).

Peanut-Free Diet

The peanut is a legume, not a nut. Legumes are edible seeds enclosed in pods and include soybeans, lima beans, carob. and sweet clover. Ingredients to avoid for those with peanut allergy include cold pressed peanut oil. ground nuts, mixed nuts, peanuts, peanut butter, and peanut flour.

The following foods or ingredients may contain peanuts or peanut products: African. Chinese, and Thai dishes, baked goods (pastries, cookies, etc), candy, chili and spaghetti sauce (may use peanut butter as a thickening agent), chocolate candies, HPP. HVP. and marzipan (usually made from almonds but can often be a mixture of nuts).

The following are important considerations for those with peanut allergy:

• Peanut allergy is not usually outgrown.

• Peanut oil is usually not a problem provided it is free of peanut protein.

• Check all candy labels since they w ill often list peanuts on the label if made in the same facility as a candy containing peanuts. For example. Plain M & M's and Raisinetts both indicate on the label that they may contain peanuts but peanuts are not necessarily included in the ingredients list.

• Avoid artificial nuts that may contain peanuts.

• Some ethnic restaurants often use peanuts in a variety of foods, making crossconlamination highly possible.

• Egg rolls arc occasionally scaled with peanut butter.

• Soy butter is available as a peanut butter substitute.

Tree Nut-Free Diet

Most nuts are the seeds or dried fruits of trees. They grow all over the world in assorted shapes and sizes. Those with nut allergy should avoid foods with the following ingredients: almonds, Brazil nuts, cashews, filberts, hazelnuts, hickory nuts, macadamia. pecans, pine nuts (pignoli. pinon nuts. Indian nuts), pistachios, walnuts (black & Persian). Gianduja or Nutella (a creamy mixture of chocolate and chopped toasted nuts), marzipan/almond paste, nut butters (almond, cashews), nut oil. and nut paste. It should also be noted that:

• Artificial nuts consist of a variety of nuts ground and reshaped into other nuts.

• Natural extracts such as almond extract and natural vvititergreen extract (usually made with filbert/hazelnut) should be avoided.

• Imitation rather than natural flavoring should be used.

• Nuts are added to a v ariety of foods, cereal, crackers, wheatless cakes, ice cream, and baked goods.

• Nuts are used in many ethnic dishes.

• Coconut, nutmeg, and water chestnuts are not in the tree nut family.

Shellfish-Free Diet

Edible shellfish are usually divided into two categories, mollusks and crustaceans. Mollusks such as clams and mussels have two shells: the abalone, which has a shell covering and a soft underparl. is also considered a mol-lusk. Crustaceans have segmented bodies covered with an armor-like section of thick and thin shells (eg. lobster). Those with shellfish allergy should avoid the following ingredients: abalone, clams (cherrystones, little-neck. pismo. quahog, surf clam, steamer, geoduck. razor, mud. and white), crab (Atlantic blue crab, soft-shell crab, stone crab), crawfish (crayfish, ecrevisse). lobster (spiny or rock lobster), mussels, oysters (blue points, lynnhavens, chincoteagers). scallops (bay, sea. and calico). mollusk, shrimp (prawn, crevette), and cockle (periwinkle, sea urchin).

Soy-Free Diet

The soy-free diet is a modification of the normal diet with the elimination of soybeans and all foods containing byproducts of soybeans. Soybeans are a legume and are a staple of Asian diets. Those with soy allergy should also avoid the following ingredients: edamame (green vegetable soybeans), hydrolyzed soy protein, lecithin (extracted from soybean oil and used as an emulsifier). natto (made from fermented whole cooked soybeans), miso (a rich salty condiment used in Japanese cooking), soya, soy sauce (tamari, shoyu. teriyaki), soy fiber (okra, soy bran, soy isolate fiber), soy flour, soy grits, soy milk, soy nuts, soy sprouts, soy protein concentrate, soy protein isolates, soy oil. tempeh (Indonesian—a chunky, tender soybean cake), textured vegetable protein (TVP). tofu (soybean curds), and yuba (made by lifting and dry ing the thin layer formed on the surface of cooling soy milk).

The following foods or ingredients may contain soy protein: flavoring. HVP. HPP. natural flavoring, textured soy protein (TSP). textured soy flour (TSF). vegetable broth, vegetable gum. and vegetable starch.

Most people with soy allergies may safely eat soy leeithin and soy oil. Soy lecithin is a mixture of fatty substances. a byproduct of soybean processing. Lecithin is often used as a stabilizer, emtilsifier, or an antioxidant.

Wheat-Free Diet

The wheat-free diet is a modification of the normal diet with the following ingredients eliminated: bread crumbs, bran, bulgur. cereal extract, cracker meal, enriched Hour, larina. Hour, gluten (protein in wheat), graham Hour (can be a blend of flours containing wheat), mat/o or niatzo meal, high gluten Hour, high protein Hour, malt vital gluten, wheat bran, wheat grain, wheat gluten, wheat starch, and whole wheat Hour.

The following foods or ingredients contain wheat proteins: gelatinized starch. HVP. modified food starch, natural flavoring, soy sauce, starch, vegetable gum. and vegetable starch.

It should also be noted that:

• One cup wheat flour can be substituted by 1/2 cup oat flour and 1/: cup rice flour.

• Ethnic cookbooks contain many wheat-free recipes (eg. Hispanic/Latino and Asian cookbooks often use rice).

• Spaghetti squash and corn or rice pasta may substitute for regular pasta.

• Fresh, fro/en. and canned vegetables are usually wheat-free whereas prepackaged vegetables in sauces often contain wheat as tiller.

• Gluten-free means wheat-free.

• Triticale is a cross of wheat and rye.

References

1. Sampson HA. Metcalf DP. Food allergies. JAMA 1492; 268:2840-4.

2. Bock SA. Sampson HA. Food allergy in infancy. Pediatr Clin Norlh Am 1994:41 (5): 1047-67.

3. Young E. Stoneham MD. Pelruckevitch A. el al. A population study of food intolerance. Lancet 1994:343:1 127-30.

4. Goldman AS. Kantak AG. HamPong AJ. Goldblum RM. Food hypersensiti\ ities: historical perspectives, diagnosis and clinical presentations. In: Brostoff J. Challacombe SJ. editors. Food allergy and intolerance. London: Bailliere Tindall; 1987. p. 797-805.

5. Stern M. Allergic enteropathy. In: Walker WA. Dune PR. Hamilton JR. et al. Pediatric gastrointestinal disease. 2nd ed. St. Louis: Mosby: 1996. p. 677-92.

6. Patrick MK. Gall DG. Protein intolerance and inimunocyte and enterocyte interaction. Pediatr Clin North Am 1988: 35(11:17-34.

7. Lake AM. Whitington PF. Hamilton SR. Dietary protein-induced colitis in breastfed infants. J Pediatr 1982:101: 906-10.

8. Odze RD. Wershil BK, Leichtner AM. Antonioli DA. Allergic colitis in infants. J Pediatr 1995:126:163-70.

9. Vanderhoof JA. Murray ND. Kaufman SS. el al. Intolerance to protein hydrolysate infant formulas: an under-recogni/ed cause of gastrointestinal symptoms in infants. J Pediatr 1997:131(5 ):741 -4.

10. Sampson HA. IgE-mediated food intolerances. J Allergy Clin Immunol 1988:81:495-504.

11. Watson WTA. Food allergy in children. Clin Rev Allergy Immunol 1995:13:347-59.

12. Regenstein JM. Are "pareve" products really milk-free'.' Food Allergy News 1998:7(6): I.

Additional Resources

National Support Groups

The Food Allergy Network

4744 Holly Avenue

Fairfax. VA 22030-5647

Fax 703-691-2713

Website http://www.foodallergy.org.

The Food Allergy Network (FAN) is a national nonprolit organization established to help families living with food allergies and increase public awareness about food allergies and anaphylaxis. The focus is on children hut there are many adult members. All the resources are checked for medical accuracy by FAN's nine-member medical advisory board. There is a subscription fee.

Allergy and Asthma Network/Mothers of Asthmatics, Inc.

104(H) Eaton Place Suite 107

Fairfax. VA 22030

703-691 -3179 or 800-929-4040

The Allergy and Asthma Network/Mothers of Asthmatics. Inc. publishes a monthly newsletter with practical information for patients and families. Books, videos, and other educational materials available are also available.

Other Organizations Nut Allergy

Vermont Nut Free Chocolates. P.O. Box 67. Grand Isle. VT 05458. I -888-4-NUT-FREE. phone/lax: 802-372-4654. email: vtnutfreeS'aol.com/

Soy Allergy

Indiana Soybean Board. U.S. 1998 Soyfoods Directory. Stevens and Associates. Inc..

4816 North Pennsylvania Street. Indianapolis. IN 46205-1774. Website: http://www.soyfoods.com/

Internet Resources

Milk Protein Allergy

http://www.non-diary.org/

http://www.tofutti.com/

http://www.whitewave.com/

http://www.vegetariantimes.com/

http://www.ehoclat.com/

http://uu v..navigator.tufts.edu/ (a rating guide to nutrition websites) http://w ww.eatright.org/ (The American Dietetics Association)

Peanut Allergy

http://www.peanutallergy.com/

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Responses

  • clinton
    What allergans are in pn nutrition?
    3 years ago
  • Cerys
    Can a patient that has allergies to eggss be administered total parental nutrients?
    2 months ago

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