Peanut & Nut Allergy

By Dr. Mubarak Mavani

Food allergies are nothing to sneeze at. Their symptoms - nausea, itchy hives, breathing difficulty, and swelling - are miserable. In extreme cases, allergies can be deadly. In sensitive people, the body makes allergy-type antibodies specific to food proteins. If a person with a food allergy eats the specific food, the allergy-causing food proteins react with these antibodies, triggering an allergic reaction that includes release of histamine and other chemicals. Release of these substances can cause a host of uncomfortable symptoms affecting your skin, cardiovascular or respiratory system or stomach and intestines - usually within minutes of eating, but almost always within 2 hours.

However, it may be only seconds before someone with a severe allergy may experience an anaphylactic (a-na-fi-LAK-tik) reaction. In this life-threatening condition, the respiratory or circulatory systems may be seriously affected. The airways in the lungs may constrict and the soft tissues in the throat may swell, making it difficult to breathe. The heart beats rapidly, and dizziness or fainting may follow. Immediate medical attention is essential for a life-threatening anaphylactic reaction.

Any food can cause a food allergy. But few actually are proven to trigger reactions. The most common offenders are peanuts, tree nuts, shellfish (especially shrimp), whitefish, milk and eggs.

Peanuts, nuts and seeds (such as Sesame and Sunflower seeds) can cause a severe allergy which can be life threatening and needs immediate medical attention. A research study in Cambridge (Ewan, 1996) concludes that allergy to nuts, mainly peanuts, is occurring in very young children, that peanut and nut allergies are becoming more common and that with time, multiple peanut/nut allergies are appearing.

Symptoms of peanut allergy include vomiting, diarrhoea, and swelling of the face, throat and acute abdominal pain. The first symptoms may include sneezing and a tingling sensation on the lips; tongue and throat, followed by pallor, feeling unwell, warm and light headed. The danger signs are difficulty in breathing, pallor and shock. This reaction needs to be treated immediately with adrenaline injection. Always ring a doctor immediately or seek emergency medical help if you have any suspicion of an allergic shock reaction.

Ewan investigated 62 cases of suspected nut allergy. Some proved to be allergic to more than one type of nut. Peanuts were the commonest cause of allergy (47 cases), followed by Brazil nuts (18), Almonds (14) and Hazelnuts (13). The onset of allergic symptoms occurred by the age of two years in 50% of the patients and by the age of seven in the vast majority of cases. Peanuts accounted for all nut?related allergies in children sensitised in the first year of the life and for 82% of allergies in children sensitised by the age of three years.

Measures to be taken to reduce the risk of nut/peanut allergy:

1. Avoidance of peanuts/nuts by young children, particularly by those with other allergies such as hay fever, asthma and eczema.
   
2. Any child allergic to peanuts should avoid all peanuts and nut products for three to five years.
   
3. The airline meal ingredients and peanut dust recirculating in the cabin air from packets of peanuts can pose a risk during plane journey. Special request to the airline can be made to remove peanuts from the plane; it must be supported by a doctor's certificate.
   
4. Inform playgroups, schools, workplace, friends and relatives. The parents and careers of allergic individuals should know how and when to give adrenaline and antihistamine.
   
5. Education about food sources is essential as peanut and nut products may be encountered at any meal. Do not risk testing food by eating small amounts. The best policy is to speak with the person responsible for preparing the food.
   
6. Simply removing peanuts from a dish of nuts does not remove the contaminated protein; peanut oils can also be contaminated with peanut protein, as can utensils used to cook foods containing peanuts.
   
7. During pregnancy, if a mother who is not affected herself has a child with peanut allergy, it is sensible to avoid peanuts during future pregnancy and breast feeding, and to select infant foods that do not contain peanuts or peanut oil.
   
8. Join Medic Alert and obtain a Medic Alert emblem, worn as a bracelet or medallion. Engraved on the back of the emblem is the member's medical condition, a personal identification number and a 24-hour telephone number.
   
9. Those who know that they may suffer from a severe allergic reaction to peanuts must ensure that they carry adrenaline with them at all times, as prescribed by their GP or consultant. It could be a matter of life and death.
   

Ref: NIS/9/96 Spring/Summer 96 Quarterly Review
Dr P Ewan, Addenbrooks Hospital, Cambridge 

HIB - Health Advice