Allergy is an evolving disease affecting babies, young children and adults. Food is a common cause of allergy for children less than three years of age, while house dust mites, pets dander, moulds, grasses and pollens are the most common allergens among older children. For adults, the common allergens are house dust mites and moulds.
Allergy is a multi-organ disease which affects the eye (allergic conjunctivitis), nose (allergic rhinitis), ear (otitis media), skin (eczema) and gut (colic, diarrhoea and bloating). Allergic rhinitis or hay fever causes nasal itching, congestion, sneezing, post nasal drip, running, watery discharge and cold/flu like symptoms. Sinusitis is often a complication of allergic rhinitis.
Allergies in the eyes will have conjunctivitis symptoms such as itching, redness, swelling and tearing. There are three types of skin allergies: hives, contact dermatitis and eczema. Hives (urticaria) are itching wheals of varying sizes that may appear on the skin, lips and inside of the mouth and ears. Contact dermatitis is blistery rash with intense itch caused by substances such as poison ivy, while eczema appears as a dry itchy rash often along creases of the skin, but can also be found on most other parts of the body.
Asthma is caused by allergies in the lungs. The symptoms of asthma are shortness of breath, wheezing, tightness in the chest and cough. Allergies in the gut will cause stomach cramp, vomit- ing and diarrhoea with sensitivity to foods. Ear allergies will cause infection and middle ear fluid whilst some other allergies will cause headache, fatigue, hyperactivity and depression.
Allergies can affect many parts of the body, and therefore it is difficult to diagnose. Some of the symptoms may be similar to other health conditions such as the common cold and flu. If a condition persists, occurs frequently, and the person has a family history of allergy, it is best to consult a doctor as soon as possible. This is because the more the symptoms, the longer the duration of suffering.
The year-round warm, humid climate in Singapore is conducive for the proliferation of dust mites and moulds which are the most common aeroallergens. Most people are not aware that a double bed can have two million dust mites. Dust mites live in mattresses, carpets, upholstered sofas and the innocent stuffed toys/animals.
There is a global increase in rhinitis across many countries espe- cially in urban populations such as Singapore. About 13.1 per cent of the population in Singapore suffer from rhinitis. Incidence of allergies amongst Singaporean children is high – 45 per cent have allergic rhinitis; eczema, 20.8 per cent; asthma, 20 per cent; and food allergy, 4 to 5 per cent. Allergic rhinitis can cause poor sleep (with or without snoring), lack of concentration, daytime sleepiness and long-term chronic sinusitis.
Based on a skin prick test (SPT), the following is the ranking of food-based allergens amongst children – shellfish, milk, egg, wheat and peanuts. Fish allergy is rare in Singapore.
The long term solution in the management of allergic rhinitis and asthma is to reduce dust mites, control humidity at home, and vacuum the house with HEPA (highly efficiency particulate air) filter.
Although pharmacotherapy can relieve and control symptoms, it does not cure the condition. It also does not reverse the trend for the growing incidence of respiratory allergic diseases. On the other hand, specific immunotherapy treats the root of the problem. It relieves symptoms, decreases the need to use medi- cations, and can also prevent the progression of allergies. It has been shown to be effective in adults and children with allergic rhinitis and asthma caused by grasses, pollens and dust mites.
Allergic asthma and rhinitis is an increasing global health problem affecting 8 per cent to 35 per cent of the world population. If left untreated, it affects social life, school performance and work productivity. As such, the overall cost (direct and indirect) has become an increasing burden for the community and the patient.