The following 10 questions are among those frequently asked by food allergic people or their carers, through calls made to the Anaphylaxis Campaign helpline. Our answers have been reviewed by experts in the medical field and food industry. Brief medical references are given in brackets, with full references at the end.
Are children with nut allergy at risk from conkers?
A few schools have banned games with conkers because they are worried they will endanger pupils with nut allergy. However, we can find no credible reports suggesting that conkers pose any risk to people with nut allergy.
Staff operating our telephone helpline have heard a few anecdotal reports from people saying they have skin reactions to conkers when they handle them. Our lead medical reviewer believes this to be a rare problem occurring equally in people with and without nut allergy. Clearly if this happens, they should be avoided. No one should be eating them as they are poisonous in their own right.
Should people with nut allergy avoid nutmeg?
Because of its name, many people with nut allergy believe that nutmeg must be avoided at all costs. It is possible that they are being over-cautious because there is no hard evidence to suggest that people with nut allergy are particularly at risk from nutmeg, and the incidence of nutmeg allergy is thought to be rare. However, not enough research has been carried out to be certain about how much of a problem it is. Nutmeg is the kernel of an apricot-like fruit and there is just the possibility that there might be cross-reactivity with almond, which is also a fruit kernel. If you are allergic to nuts and have never had a reaction to nutmeg it is likely that nutmeg poses no greater risk than many other foods. However, it would be sensible to be cautious, particularly if you are allergic to almonds or other fruit kernels such as apricot.
The most common oils used in the UK are derived from rapeseed, sunflower seed, soya, maize, palm and palm kernel. Where these oils appear in pre-packed food, they are likely to have been refined — a process that removes any detectable traces of proteins (the components of a food responsible for triggering allergic reactions). There is some research to support the view that refined vegetable oils are safe for people with food allergies. For example, a project carried out in Southampton showed that refined peanut oil will not cause allergic reactions for the majority of people with peanut allergy and if anyone does suffer a reaction it is likely to be mild (Hourihane et al 1997). Although it is impossible to be 100 per cent certain, it is highly unlikely that vegetable oils, when refined, will cause allergic reactions. However, to be absolutely certain about this, research would have to be undertaken on every oil. Some speciality oils (for example, sesame, hazelnut and walnut) contain unrefined oil and certainly do present a risk.
(The above text was checked for accuracy by the Seed Crushers and Oil Processors Association).
The tendency to be allergic runs in families. If one family member has a food allergy (father, mother or a child), then all children in the immediate family will also be susceptible to allergies and could possibly become allergic to something. This will not necessarily be an allergy to the same foods as others in the family, and it does not necessarily follow that if one family member has an allergy that is severe, any other allergies in the family will also be severe.
The Campaign knows of a small number of cases where touch or smell caused severe reactions for people with peanut allergy.
However, some reassurance can be gained from an American study (Simonte et al, 2003). Researchers observed 30 children with severe peanut allergy while they were being exposed to peanut butter through touch and smell. Accidental contact was simulated by pressing a dab of peanut butter on the child’s back for one minute, and by holding a dish containing three ounces of peanut butter one foot from the child’s nose for 10 minutes.
- None of the children experienced anaphylaxis.
- There were no reactions to inhalation.
- During the touch part of the study one-third of the children had a mild reaction, such as redness, itching, or a single hive limited to the site of contact. Medication was not needed to treat these reactions.
The researchers concluded that at least 90 per cent of children with the same severity of peanut allergy would not experience a severe reaction to similar exposures. They emphasised that the study looked at peanut butter but not peanut in other forms.
We strongly advise that people with peanut allergy should discuss their own individual case with their allergy specialist before changing their allergen avoidance measures.
In our experience, the number of people with peanut allergy who react to other legumes (such as soya, peas, chick peas, fenugreek, beans and lentils) is relatively small and this is supported by research from the USA (Sicherer, 2001). Care is needed, but most people find they can tolerate other legumes without problems. It is important to raise this with your allergy specialist for specific advice.
The use of “may contain” warnings is voluntary and not directly covered by food labelling law. Nevertheless industry is well aware that the General Food Law places a requirement on manufacturers to communicate any risk to consumer health following the consumption of their product.
Many people find “may contain” warnings annoying because they limit choice and make shopping complicated, but often these warnings are there for a good reason because of the risks of cross-contamination during the production chain. Our advice to people is clear: Don’t ignore these warnings. You may eat a product numerous times without having a reaction but the next time you may not be so lucky. Cross-contamination can be intermittent. Research has shown that the greatest risk of cross-contamination occurs with snack foods (Brough et al, 2015).
Although research is ongoing, there is no evidence at present to suggest that mothers who eat peanuts while pregnant or breastfeeding will increase the risk of their child becoming allergic to peanuts. This includes women in “high risk” families — that is, where there is already allergy.
Guidelines issued by the European Academy of Allergy and Clinical Immunology (EAACI) state: “The advice for all mothers includes the consumption of a normal healthy diet without restrictions during pregnancy and lactation (breastfeeding).” (Muraro et al 2014).
The companies that produce the three adrenaline injectors available in the UK also produce “dummy” devices for people to practise with. The details are on their websites.
Brough, H. A., Turner, P. J., Wright, T., Fox, A. T., Taylor, S. L., Warner, J. O., & Lack, G. (2014). Dietary management of peanut and tree nut allergy: what exactly should patients avoid? Clinical & Experimental Allergy.45. (5) pp.859-871
Muraro, A., Halken, S., Arshad, S.H., Beyer, K., Dubois, A.E.J., Du Toit, G., Eigenmann, P.A., Grimshaw, K.E.C., Hoest, A., Lack, G., O’Mahony, L., Papadopoulos, N.G., Panesar, S., Prescott, S., Roberts, G., de Silva, D., Venter, C., Verhasselt, V., Akdis, A.C., Sheikh, A. on behalf of EAACI Food Allergy and Anaphylaxis Guidelines Group (2014) EAACI Food Allergy and Anaphylaxis Guidelines. Primary prevention of food allergy. Allergy. 69. p.590—601.
Hourihane, J.O., Bedwani, S.J., Dean, T.P., Warner, J.O.( 1997). Randomised, double blind, crossover challenge study of allergenicity of peanut oils in subjects allergic to peanuts. BMJ. 12. 314(7087), p.1084-1088.
Sicherer, S.H (2001) Clinical implications of cross-reactive food allergens. Journal of Allergy and Clinical Immunology. 108 (6) p. 881-890.
Simonte, S.J., Ma, S., Mofidi, S., Sicherer, S.H. (2003). Relevance of casual contact with peanut butter in children with peanut allergy. Journal of Allergy and Clinical Immunology. 112. (1) p.180
Our text has been peer-reviewed by Prof John Warner, Professor of Paediatrics and Head of Department, Imperial College. He has no conflicts of interest to report.
Other experts in various fields were asked for their opinions on specific sections. These included a representative of SCOPA, the Seed Crushers and Oil Processors Association (section on vegetable oils). The author felt it relevant to record this as SCOPA is a trade body.
Publication date: December 2015
Review date: November 2018