Allergies affect millions of people worldwide ranging from minor allergy-like allergic rhinitis to a chronic allergy such as atopic asthma. Allergies can even cause hospitalisation and death in a severe form called anaphylaxis. A person develops an allergy when the immune system over-react to a stimulus called allergen.
Allergy can be acute or chronic in nature. The former is quite common where the onset is usually within seconds to minutes from when contact with the allergen is made. Tackling allergies is not easy since a lot of patients do not know what triggers their allergy. So, how does one reduce their allergic symptoms and treat them?
- Antihistamines
This is a class of drug that acts on the H1-receptor. Antihistamines such as Loratadine and Cyclizine works by inhibiting the H1-receptor from being activated. This receptor is present in mast cell, vascular wall and smooth muscle. The resulted action causes the mast cell to unable to release histamine which is the main principle of the acute allergic symptoms.
In addition, the drug also binds to the receptor of the vascular wall hence making it non-permeable to intracellular fluid (fluids inside the blood vessel) from being leaking out. This lead to cessation of symptoms such as the runny nose, watery eyes and wheals. Antihistamines are easy to use and need no prescription but caution should be advised due to its effects such as somnolence.
- Corticosteroids (steroids)
Steroids are the wonder drug in the medicine world. Corticosteroid drug has a similar structure to our own steroid hormone. It functions to halt the white cell activity such as stopping the inflammatory and allergic chemical mediators like prostaglandin and leukotrienes, preventing white cell recruitment and migration and also preventing vascular leakage.
Corticosteroids can work when other medications like the antihistamines are not effective. It is one of the medications used in the severe allergic reaction (anaphylaxis). It is also sometimes being used for a chronic allergic condition. However, chronic use of corticosteroids poses problematic effects on the health of the user. Common long term side effects of corticosteroid are like weight gain, easy to get infection, depression, thin skin and diabetes.
- Leukotriene Receptor Antagonist (LTRA) and Omalizumab
LTRA like Montelukast works by blocking the type I receptor thus preventing the release of leukotrienes. Omalizumab, on the other hand, is a monoclonal antibody that works by binding to the specific immune protein, IgE. Both LTRA and Omalizumab are used in chronic allergic condition most commonly in chronic atopic asthma.
- Desensitization therapy
The principle of desensitization therapy is based on the hygiene hypothesis. The hypothesis stated that the lack of exposure to common allergens among the individual cause the immune system to take other pathways of maturity and identify the allergens as a threat.
The therapy works only in allergic reaction mediated by IgE pathways such as allergic rhinitis and insect sting. The therapy is applied in a controlled manner where the allergen is given in a small amount in increasing doses over a period of months. This is to ensure the immune system recognise it slowly without causing any unwanted adverse reactions.
Allergies are sure problematic for some people. To ensure better treatment and management of allergies, consultation with a doctor is a must. People nowadays can go to the internet and search relevant and trustworthy site to ask medical questions such as ask queries to DoctorOnCall.
