Food allergy is on the rise, and someone with food allergy can present to a skin specialist, physician, child specialist and sometimes even a surgeon. Urbanization, environmental pollution, promoting caesarian delivery, changing food habits, etc. contribute to sharp rise in food allergy in recent past. Being a less discussed entity, patient might be unaware of the actual cause of this distressing health issue.
What is food allergy!
Food allergy is an abnormal reaction to food, triggered by our immune system. Immune system is our body’s defense mechanism against harmful threats such as bacteria, viruses, etc. When this defense system reacts against certain food components, it manifests as allergy. Common symptoms of food allergy are stomach upset, pain abdomen, itchy skin rash, blood in stool, diarrhea, difficulty breathing, swelling of face, unexplained fatigue, irritability, etc. Symptoms of food allergy usually begins in childhood, but can also start later in life.
There are range of delayed onset food allergies that appear as late as one week after food intake. It is difficult to point at the triggering agent in such situations. Moreover, some people show symptoms without an actual allergy. It is due to intolerance to certain food components. For example, intolerance to lactose component in milk, manifests as diarrhea within few hours of milk consumption. Also, some foods directly produce chemicals such as histamine, mimicking symptoms of allergy. Foods such as wine and pickles cause itchy mouth, sneezing or difficulty breathing promptly. This reaction is dependent on amount ingested. This is not exactly food allergy. Your doctor will be able to tell you precisely.
Foods associated with allergy
Common food allergens in our circumstance are cow milk, egg white, peanuts, fish, wheat, soy bean, dairy products such as cheese, etc. Other allergens are raw fruits and vegetables, tomatoes, chocolate, legumes, lemon, etc. Some foods such as meat, vegetables and fruits can be rendered harmless via cooking, because their allergenic components are destroyed by cooking. Food products such as preservatives, colorants, flavor enhancers such as cinnamon, menthol, vanilla, food additives, wine, dried fruits, pickles, strawberry, etc can directly stimulate symptoms similar to food allergy.
Who gets food allergy??
Small infants and children are more prone to food allergy. Some foods such as cow milk and egg white cause specific symptoms from early childhood. Early introduction of solid foods or formula milk products before six months of life has been associated with development of allergy. Children with history of allergy in family members are at more risk.
Adults can also commonly develop specific food allergies later on.
Generally, someone with one food allergy might also have other food sensitivity. Having said that, all potential food allergens do not cause symptoms in everyone.
COW MILK PROTEIN ALLERGY
Cow milk protein allergy is common in developed world, while it is rising in our part of the globe. It is not always diagnosed as we do not suspect food allergy frequently in our scenario.
It usually begins within first year of life, and occurs within a week of introducing foods containing cow milk protein. Children typically present to a doctor with diarrhea, vomiting, bad stomach ache or blood in stool within few hours of consuming cow milk or formula feed. Other symptoms are crying inconsolably, irritability, skin allergies, such as itchy hives and eczema, swelling of eyes and lips, shortness of breath, etc.
Children who are not exclusively breastfed for at least first four months of life are at more risk. Components of cow milk protein are present in common formula feeds available in the market, affecting children who are put on these feeds. Cow milk protein is also present in skimmed milk, butter, curds, cheese, yogurt, beverages, burgers, etc. Older children may have eating difficulties, avoiding certain foods, poor weight gain, etc. Do not force your child to eat foods he denies or refuses consistently. Children are often unable to express the discomfort or symptoms accurately.
A doctor makes a diagnosis based on patient’s complaint, previous episodes and careful examination of the patient. Tests such as skin prick tests, specific blood tests (IgE antibodies) help in confirming cow milk protein allergy. These tests are available in few hospitals and laboratories in Nepal. It is not always mandatory to have tests for the diagnosis.
Treatment is avoidance of the food trigger. Exclusive breastfeeding for at least 4 months, and preferably 6 months seem to be protective. In circumstances where exclusive breastfeeding is not possible, it is important to choose formula feed vigilantly. Common formula feeds are not recommended. Partially hydrolyzed infant formula or “hypoallergenic” formula milk should be chosen. Soy formula or litho can be a reassuring alternative in our scenario. However, 10-30% children with cow milk protein allergy also cross react to soy proteins. Replacing cow milk with goat or sheep milk isn’t recommended. On brighter side, cow milk protein allergy generally improves by 6 years of age. But there is no specific age for reintroducing cow milk in diet.
Other food allergies common in childhood are egg white and peanut allergy. While peanut allergy is a menace, children might develop tolerance to egg whites similar to cow milk. Doctors usually advice patients to avoid problem foods, however, a recent study showed that exposing young child with small amounts of culprit foods, eg peanuts, help them develop tolerance to that specific allergenic food.
Another aspect of food allergy is whether we can predict them before they happen. The answer is no, except in few instances, where parents or other family members have similar problems. Children with dry skin, reactive skin and asthma have increased likelihood of developing allergies as adults. But no one can exactly anticipate it before it happens. Parents have to be alert and cautiously follow their child’s relevant symptoms in relation with food intake.
Hence, food allergy is less commonly discussed, not so uncommon health problem.