Allergies are due to a damaging immune response by the body to different substances such as dust, fur, pets, cold and food. This leads to hypersensitivity ( undesirable reactions produced by the normal immune system) of the body to the substance. Allergies are among the most common chronic conditions worldwide. Worldwide, the rise in prevalence of allergic diseases has continued in the industrialized world for more than 50 years, sensitization rates to one or more common allergens among school children are currently approaching 40%-50%. In 2012, 10.6% or 7.8 million children were reported to have respiratory allergies in the past 12 months.
When a person comes in contact with a substance he is allergic to, the substance attaches to a cell in the blood stream called mast cell. The mast cells respond by releasing various substances into the blood stream such as histamine. This will then lead to the various allergic responses.
Signs and symptoms
Allergic reactions manifest with various symptoms. It can affect any organ in the body and they are manifested when there is exposure to the allergen (allergy trigger). The various signs and symptoms of allergic reaction include;
- Nose; running nose, sneezing, swelling of airway
- Eyes; red eyes, itching conjunctiva, watery eyes
- Chest; wheezing, dyspnea as seen in asthma, airway obstruction, coughing, chest tightness,
- Sinuses; allergic sinusitis
- Gastrointestinal system; vomiting, diarrhea, abdominal pain, swollen tongue, bloating, swelling of the lip, tongue and throat
- Skin; rashes, itchy skin, swelling of the skin (hives), eczema
- Ear; ear fullness, ear pain, difficulty with hearing due to obstruction of the Eustachian tube
- Severe allergic reaction can lead to; low blood pressure, coma, and death.
There are various substances that can cause allergic reaction and they include;
- Air pollutants such as; dust, smoke
- Mite protein
- cold air
- food such as peanut, milk,sea food, egg white,
- drugs; quinines, penicillin
Genetic; allergic diseases are strongly familial, identical twins are 70% likely to have the same allergic diseases. Also, similar allergic diseases occur in about 40% of non-identical twins. Allergic parents are more likely to have allergic children
For many people the exact allergen might not be readily known. A good history and examination is needed to make a good diagnosis. Also, some test can be done to identify the exact allergen. They include;
- Skin prick test; various likey allergens are injected into the body at labeled sites in small quantity. The body’s response is then noted to determine which allergen the person is sensitive to.
- Patch test; this is done in case of skin allergic reaction. Different allergic patches are placed on the skin and are then observed to know which one the person is sensitive to.
- Blood test; your blood can be examines for common allergic agents.
Once the trigger has been discovered its best you stay away from it.
Delayed introduction of adult meals in babies till about 6 months reduces the chances of having allergic reactions later in life. Breastfeeding is therefore a protective factor.
The treatment depends on the cause of the allergy and the severity. Certain medications can be used to reduce the allergies and they include;
- Antihistamine; such as loratidine, chlopheniramine. They shouldn’t be taken for more than a week.
- Nasal decongestant; can be used to clear blocked nose
- Creams and lotions such as calamine lotion and moisturizing cream can be used to treat red and itchy skin caused by an allergic reaction.
- Steroids; they help to reduce the inflammatory response to allergic reactions.
Severe allergic reaction is an emergency which can lead to life threatening condition known as anaphylactic shock. It is important you go to the hospital for prompt management.