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b. Other products:

  • Peanut flour is obtained from grinding peanuts and is used as an abrasive, a bulking agent and a viscosity-increasing agent.

  • Hydrolyzed vegetable protein is used to flavor foods. The source is usually soya or wheat, but can be also be peanut.11

  • Peanut and peanut products are used in some animal and bird foods.11

  • Restaurants may use peanut butter to thicken sauces; peanuts and peanut butter may be used in the glaze on roast meat, or in cakes, cookies and candies; potato chips and French fries and other fried food may be fried in peanut oil; also, the oil in a deep fat fryer that has been used to fry peanut-containing food (e.g., vegetarian burgers), and is then reused may contaminate food.10 Some oriental restaurants use peanut butter to "glue down" the ends of egg rolls to stop them from coming apart in the cooking process.5

  • Chinese, Thai, Malaysian and Indian restaurants use peanuts and peanut products in many of their dishes.11

  • Almond powder and chopped almonds imported from Asia sometimes contain powdered or chopped peanuts as a filler.10

N.B.: E471 (a monoglyceride of fatty acids) and E472's (either lactic acid esters of diglycerides; acetic and tartaric acid esters of glycerides/DATEM; acetyl tartaric esters of glycerides; acetyl tartaric esters of glycerides; acetic acid esters of diglycerides; or citric acid esters of diglycerides) are food emulsifiers that would be acceptable for peanut allergic patients to use. If peanut oil was used as the source in these additives, the risk of an allergic reaction would be extremely low, as the oil would have been refined.31

Peanuts can be concealed in different kinds of foods because they are rich in protein, are often used to change the viscosity of other foods, and can be used as substitutes for more expensive products. American and Asian cuisines especially use peanuts in a wide variety of recipes.33Sometimes no differentiation is made in marketing peanuts and other nuts, and the two are sold together in "nut mixtures". Contamination can occur in the processing of nuts and nut-containing products. Utensils used to handle peanuts can be used on "bulk nuts" without cleaning intervention. In the manufacture of confections such as candies and ice creams, cross-contamination between nuts and peanuts can also easily occur. It is thus suggested that persons with severe peanut allergy avoid products containing any type of "nuts" because of the danger of traces of peanuts.9

"Mandalona" nut is one of the names given to a manufactured product made from de-flavored, de-colored peanut meal that is pressed into molds, re-flavored and colored, and sold as a substitute for tree nuts such as walnuts, almonds and pecan nuts.9

Conditions that have been associated with adverse reactions to peanut:

  • Adverse reactions to peanuts have been observed through dermal contact, inhalation and ingestion of peanuts, peanut oil, peanut-containing products and/or peanut dust.12,34,35,36

  • Peanut allergens have been transmitted to allergic individuals by kissing, by eating from the same food utensil that has been in contact with peanuts, and also by playing cards.37,38

  • Contact has occurred through peanut oil-containing ointments and massage oils.36

  • In-flight allergic reactions to peanuts have been reported from ingestion, dermal contact, and inhalation in airplanes.12,39

  • Adverse reactions to peanuts can be hastened following alcohol ingestion, the taking of aspirin and exercise (food-dependent exercise-induced reaction). The first two increase gut permeability and the last increases blood flow in the body.5,40,41,42,43

  • Occupational exposure can occur to peanut allergens or to the mold on peanuts; animal, cosmetic, dock, refinery, chemical and laboratory workers are susceptible.

  • Asthmatics with peanut sensitivity appear more likely to develop fatal reactions. This is probably due to the sensitivity that asthmatics have to endogenous mediators such as histamine, leukotrines and prostaglandins produced by acute food allergic reactions.1,5

  • There have been reports of transfer of symptomatic peanut allergy from the bone marrow transplant donor to the recipient,44 as well as to the recipient of a combined liver-and-kidney transplant.45

  • Proteins from peanut in a mother's diet can be passed through the breast milk and cause allergic reactions in the breastfed infant. The elimination of peanut and peanut-containing foods from the mother's diet should alleviate the problem.9 The younger a person is at his/her first exposure to peanuts, the earlier the onset of symptoms. Exclusive breastfeeding does not protect an infant against the development of peanut sensitization. Sensitization is more likely to occur the more frequently the mother eats peanuts during her pregnancy and the earlier peanuts are introduced to the infant's diet.46,47 It has also been shown that peanut allergy now presents earlier in life, possibly due to increased consumption of peanut by pregnant and lactating mothers.48 The incidence has increased with succeeding generations, and this may also be because of the increasing exposure of children to peanuts at a young age.49

Non-allergic reactions to peanut

a. Histamine
Peanuts naturally contain histamine. The storage and roasting of peanuts increase the histamine content, possibly promoting allergy-like symptoms. Histamine concentration is 0.08 - 0.56 nmol per 100 g of raw peanuts compared to 35 - 150 nmol for 100 g of roasted peanuts. Fermentation processes are likely to generate a large quantity of histamine. This could explain the differences in the intensity of the disorders occurring after ingestion of the same quantity of peanuts.25 It should also be remembered that adverse reactions to histamine occur with a dose effect. The more histamine ingested, the worse the symptoms experienced.
b. Aflatoxins
Any product can have molds that produce aflatoxins when they are stored - especially in moist conditions. High levels are most commonly found in maize, but peanuts can also contain high levels. (Peanut oils and products derived from them do not contain aflatoxins.) Authorities usually check for a safe aflatoxin level in the product. This is, however, not always done in Third World countries and rural areas. Aflatoxins have been associated with esophageal cancer. There have also been reports of cirrhosis in children caused by contaminated peanut meal. 28,50


  compiled by Karen du Plessis B.Sc. Diet.
Food & Allergy Consulting & Testing Services (FACTS)
PO Box 565
Milnerton 7435
South Africa

C. Comments by our editors

Prof Janice M. Joneja Ph. D., RDN
The topic of peanut allergy is extremely well covered in this discussion, and little remains for me to add to the information on peanut as an allergen. However, there is an important ancillary point that is mentioned, but not elaborated in the case study about which clinicians should be aware: It is not uncommon to see complete remission of eczema by removing allergenic foods from the child's and breast-feeding mother's diet, up until the age of 6 months. After this time we tend to see the influence of environmental allergies more and more as the child ages. It is uncommon to achieve complete remission of eczema by food exclusion alone in an older child, and very rare indeed in an adult. Dust and dust mite allergens, cat, dog and other animal danders, plant pollens and even mould spores tend to play an increasingly important role as eczema-triggering allergens in later life. In the search for the "culprit food", it is important that clinicians keep this in mind in order to avoid unnecessary food restrictions, and the risk of resulting nutritional deficiency.
Dr. Harris Steinman M.B.Ch.B.
Peanut allergy is of particular importance as the prevalence is increasing at an alarming rate. Health professionals need to be aware of all possible routes of exposure to the allergen that may lead to sensitisation or to an unexpected anaphylactic reaction in already sensitised individuals. Experts in this field are now recommending that pregnant and breastfeeding women, whose children are at particular risk of developing peanut allergy, avoid all peanuts and peanut containing products in their diets.

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D. References
1. Settipane GA. Anaphylactic deaths in asthmatic patients. Allergy Proc 1989;10(4):271-4.
2. Hourihane JO, Kilburn SA, Dean P, Warner JO. Clinical characteristics of peanut allergy. Clin Exp Allergy 1997;27(6):634-9.
3. Hourihane JO. Peanut allergy. Current status and future challenges. Clin Exp Allergy 1997;27(11):1240-6.
4. Hourihane JO'B, Kilburn SA, Nordlee JA, Hefle SL, Taylor SL, Warner JO. An evaluation of the sensitivity of subjects with peanut allergy to very low doses of peanut protein. J Allergy Clin Immunol 1997;100(5):596-600.
5. Loza C, Brostoff J. Peanut allergy. Clin Exp Allergy 1995;25(6):493-502.
6. Sicherer SH. Clinical update on peanut allergy. Ann Allergy Asthma Immunol 2002;88(4):350-61.
7. Spergel JM, Fiedler JM. Natural history of peanut allergy. Curr Opin Pediatr 2001;13(6):517-22.
8. Banks JR, Arnold. The Natural History of Peanut Allergy. Pediatrics 2002;110(2):433-434.
9. Joneja JV. Dietary management of food allergies and intolerances: a comprehensive guide 2nd edition. J.A. Hall Publications Ltd., Canada, 1998.
10. Brostoff J, Gamlin L. Food allergies and food intolerance: the complete guide to their identification and treatment. Healing Arts Press Rochester, Vermont, 2000.
11. Wright T. Food allergies: enjoying life with a severe food allergy. Class Publishing, London, 2001.
12. Sampson HA. Peanut Allergy. N Engl J Med 2002; 346(17):1294-9.
13. Koppelman SJ, Vlooswijk RAA. Quantification of major peanut allergens Ara h 1 and Ara h 2 in peanut varieties runner, Spanish, Virginia, and Valencia, bred in different parts of the world. {Abstract] 8th International Symposium on Problems of Food Allergy 2001,ch 11-13, Venice.
14. Park CW, Kim GI, Lee CH. A comparison study on allergen components between Korean (Arachis fastigiata Shinpung) and American peanut (Arachis hypogaea Runner). J Korean Med Sci 2000;15(4):387-92.
15. Chung SY, Maleki SJ, Champagne ET, et al. High-oleic peanuts are not different from normal peanuts in allergenicity. AAAAI 56th Annual Meeting 2000,ch.
16. Burks W, Sampson HA, Bannon GA. Peanut allergens. Allergy 1998;53:725-30.
17. Kleber-Janke T, Crameri R, Appenzeller U, Schlaak M, Becker WM. Selective cloning of peanut allergens, including profilin and 2S albumins, by phage display technology. Int Arch Allergy Immunol 1999;119:265-274.
18. Pastorello EA, Pompei C, Pravettoni V, Brenna O, Farioli L, Trambaioli C, Conti A. Lipid transfer proteins and 2S albumins as allergens. Allergy 2001;56 Suppl 67:45-7.
19. Kleber-Janke T, Crameri R, Scheurer S, Vieths S, Becker WM. Patient-tailored cloning of allergens by phage display: peanut (Arachis hypogaea) profilin, a food allergen derived from a rare mRNA. J Chromatogr B Biomed Sci Appl 2001;756(1-2):295-305.
20. Asero R, Mistrello G, Roncarolo D, de Vries SC, Gautier MF, Ciurana CL, Verbeek E, Mohammadi T, Knul-Brettlova V, Akkerdaas JH, Bulder I, Aalberse RC, van Ree R. Lipid transfer protein: a pan-allergen in plant-derived foods that is highly resistant to pepsin digestion. Int Arch Allergy Immunol 2000;122(1):20-32.
21. Asero R, Mistrello G, Roncarolo D, Amato S, Caldironi G, Barocci F, Van Ree R. Immunological cross-reactivity between lipid transfer proteins from botanically unrelated plant-derived foods: a clinical study. Allergy 2002;57(10):900-6.
22. Burks AW, Williams LW, et al. Allergenicity of peanut and soybean extracts altered by chemical or thermal denaturation. J Allergy Clin Immunol 1992;90(6 Pt 1):889-97.
23. Beyer K, Morrow E, Li XM, Bardina L, Bannon GA, Burks AW, Sampson HA. Effects of cooking methods on peanut allergenicity. J Allergy Clin Immunol 2001;107(6):1077-81.
24. Chung SY, Champagne ET. Association of end-product adducts with increased IgE binding of roasted peanuts. J Agric Food Chem 2001;49(8):3911-6.
25. Fremont S, Moneret-Vautrin DA, Zitouni N, Kanny G, Nicolas JP. Histamine content of peanuts. Allergy 1999;54:528-9.
26. Maleki SJ, Chung SY, Champagne ET, Raufman JP. The effects of roasting on the allergenic properties of peanut proteins. J Allergy Clin Immunol 2000;106(4):763-8.
27. Si-Yin Chung and Elaine T. Champagne. Allergenicity of Maillard Reaction Products from Peanut Proteins. J Agric Food Chem 1999;47(12):5227-31.
28. [No author]. Final report on the safety assessment of Peanut (Arachis hypogaea) Oil, Hydrogenated Peanut Oil, Peanut Acid, Peanut Glycerides, and Peanut (Arachis hypogaea) Flour. Int J Toxicol 2001;20 Suppl 2:65-77.
29. Teuber SS, Brown RL, Haapanen LA. Allergenicity of gourmet nut oils processed by different methods. J Allergy Clin Immunol 1997;99(4):502-7.
30. Hourihane JO, Bedwani SJ, Dean TP, Warner JO. Randomised, double blind, crossover challenge study of allergenicity of peanut oils in subjects allergic to peanuts. BMJ 1997;314(7087):1084-8.
31. Moneret Vautrin DA, Hatahet R, Kanny G. Risks of milk formulas containing peanut oil contaminated with peanut allergens in infants with atopic dermatitis. Pediatr Allergy Immunol 1994;5:184-188.
32. de Montis G, Truong M, et al. Peanut sensitization and oily solution vitamin preparations. Arch Pediatr 1995;2(1):25-8.
33. Borelli S, Anliker MD, Wüthrich B. Peanut anaphylaxis: the problem of hidden allergens. Dtsch Med Wochenschr 1999;124(41):1197-200.
34. Mathias CG. Contact urticaria from peanut butter. Contact Dermatitis 1983;9(1):66-8.
35. Tan BM, Sher MR, Good RA, Bahna SL. Severe food allergies by skin contact. Ann Allergy Asthma Immunol 2001 May;86(5):583-6.
36. Lever LR. Peanut and nut allergy. BMJ 313:299-300.
37. Lepp U, Zabel P, Schocker F. Playing cards as a carrier for peanut allergens. Allergy 2002 Sep;57(9):864.
38. Wüthrich B, Dascher M, Borelli S. Kiss-induced allergy to peanut. Allergy 2001;56(9):913.
39. Rayman RB. Peanut allergy in-flight. Aviat Space Environ Med 2002;73(5):501-2.
40. Romano A, Di Fonso M, Giuffreda F, Papa G, Artesani MC, Viola M, Venuti A, et al. Food-dependent exercise-induced anaphylaxis: clinical and laboratory findings in 54 subjects. Int Arch Allergy Immunol 2001;125(3):264-72.
41. Caffarelli C, Cataldi R, Giordano S, Cavagni G. Anaphylaxis induced by exercise and related to multiple food intake. Allergy Asthma Proc 1997;18(4):245-8.
42. Guinnepain MT, Eloit C, Raffard M, Brunet Moret MJ, et al. Exercise-induced anaphylaxis: useful screening of food sensitization. Ann Allergy 1996;77(6):491-6.
43. Cant AJ, Gibson P. Food hypersensitivity made life threatening by ingestion of aspirin. BMJ 1984 288:755-6.
44. Bellou A, Kanny G, Fremont S, Moneret-Vautrin DA. Transfer of atopy following bone marrow transplantation. Ann Allergy Asthma Immunol 1997;78(5):513-6.
45. Legendre C, Caillat Zucman S, et al. Transfer of symptomatic peanut allergy to the recipient of a combined liver-and-kidney transplant. N Engl J Med 1997;337(12):822-4.
46. Vadas P, Wai Y, Burks W, Perelman B. Detection of peanut allergens in breast milk of lactating women. JAMA 2001;285(13):1746-8.
47. Frank L, Marian A, Visser M, Weinberg E, Potter PC. Exposure to peanuts in utero and in infancy and the development of sensitisation to peanut allergens in young children. Pediatr Allergy Immunol 1999;10(1):27-32.
48. Hourihane JO, Dean TP, Warner JO. Peanut allergy in relation to heredity, maternal diet, and other atopic diseases: results of a questionnaire, skin prick testing, and challenges. BMJ 1996;313(7056):518-21.
49. Pham TS, Rudner EJ. Peanut allergy. Cutis 2000;65(5):285-9.
50. Amla I, Kamala CS, Gopalakrishna GS, et al. Cirrhosis in children from peanut meal contaminated by aflatoxin. Am J Clin Nutr 1971;24(6):609-14.

E. CPD Questions (for South African dietitians only)

This CPD session is now closed. Please contact for more information.

1. Which one of the following in not true relating to peanut allergy:
(a.) About one-third of peanut sensitive patients experience severe reactions
(b.) Symptoms can be induced after minimal contact with peanuts
(c.) Skin-prick testing do not predict clinical severity
(d.) Serum-specific IgE levels to peanut predict clinical severity

2. Peanuts are botanically related to:
(a.) tree nuts
(b.) legumes

3. To which of the following will you expect a peanut allergic individual to react to?
(a.) All species and varieties of peanut
(b.) High-oleic peanut
(c.) SunOleic peanut
(d.) All of the abov

e4. Which of the following allergens are both major allergens in peanut?
(a.) Ara h 1 and Ara h 2
(b.) Profilin and lipid transfer protein
(c.) Chitinase and sodium salicylate
(d.) Lipid transfer protein and Ara h 1

5. Which of the following is not true in a person that experiences symptoms due to lipid transfer protein, an allergen in peanut?
(a.) The person will react to raw peanut but not the heated product
(b.) The person is very likely to react to a broad range of other foods that are not related to peanut by family

6. Which of the following products do not contain peanut oil?
(a.) Creams, soaps and cosmetics
(b.) Peanut butter
(c.) Infant formulas
(d.) Vitamin tablets and drops

7. Which of the following has been associated with adverse reactions to peanut:
(a.) Kissing an individual that has been eating peanuts
(b.) Playing cards
(c.) Inhalation of airborne peanut particles in airplanes
(d.) All of the above

8. True or false: In histamine sensitive individuals, the storage and roasting of peanuts increase the histamine content of the product, causing allergy-like symptoms.
(a.) True
(b.) False


1. a [ ] b [ ] c [ ] d [X]   2. a [ ] b [X]   3. a [ ] b [ ] c [ ] d [X]
4. a [X] b [ ] c [ ] d [ ]   5. a [X] b [ ]   6. a [ ] b [X] c [ ] d [ ]
7. a [ ] b [ ] c [ ] d [X]   8. a [X] b [ ]    

1. d. Serum-specific IgE levels to peanut predict clinical severity
2. b. Legumes
3. d. All of the above
4. a. Ara h 1 and Ara h 2
5. a. When peanut is heated, the person will not react to it
6. b. Peanut butter
7. d. All of the above
8. a. True

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