Nearly 20 -30 % of children in first few years of life in western countries have some form of food allergy. By the end of the first decade this figure is reduced to less than 5 %. The majority of these allergies are not serious; by careful clinical assessment and if necessary allergy tests most children can be very easily managed. However, some reactions can be serious manifesting as wheeze as in asthma, difficulty in breathing or anaphylaxis. In the United Kingdom the commonest foods causing these severe reaction include peanuts, cows milk, eggs, shell fish, sesame, other nuts (brazil nut, hazelnut, cashew, pistachio, walnut, almond, pine nuts) and soya. Just about any food can cause an allergy and it is important to remember that there may have been tolerance to a particular food in the past with a new sensitivity developing with time.
For those children with severe allergies a normal management protocol would involve avoidance of the food concerned and prescription of anti- histamines (e.g piriton or zirtec) as well as an epipen, an injectible device containing adrenaline.
In general most cows milk (and goat milk allergy) and egg allergy disappears by about 3- 5 years. However nut and shell-fish allergy tend to be life-long. Currently, only about 10-15% of young children with peanut allergy will develop tolerance by late childhood.
Cows milk allergy can present in many different ways. It was previously understood to manifest, upon contact or ingestion, only as the typical urticarial rash with swelling of lips or tongue and some irritability. There is now increasing evidence that it can manifest as: colic; rectal bleeding (colitis), gastroesophageal reflux, failure to thrive, recurrent wheeze and other bowel related symptoms. It is distinct, and unfortunately a common source of confusion, from lactose intolerance. The latter is usually caused by the temporary loss bowel lining enzyme, lactase, following a primary viral gastroenteritis. Children with lactose intolerance will have normal allergy tests but may be intolerant to milk for usually no longer than a few weeks.
As indicated above most food allergies present from infancy disappear with time. It is normally through regular clinical assessment and the use of validated allergy tests, i.e skin prick tests, food mediated IgE tests (previously called RAST tests) and if necessary food challenges, that establishment of this tolerance to a particular food can be diagnosed.There are a number of non-validated ‘allergy tests’ in the market; my recommendation is that these are avoided as most do not have a firm researched grounding.
Considerable anxiety surrounds the use of alternative milks for cows milk allergy. There are many to choose from! It is important to remember that incorrect usage may result in nutritional problems; the commonest problem I see include rickets secondary to vitamin D and calcium deficiency. Appropriate usage is dependent on age of child, the severity of the allergy and to some extent palatability. Advice from an experienced dietitian can be extremely helpful in these situations.
Nut allergy - one of the commonest food allergies in the United Kingdom
Fruit allergy, e.g kiwi, avocado and pineapple is common. Watermelom allergy is rare.
An allergic reaction here could be due to egg, peanut, cows milk protein or chocolate