martes, 23 de octubre de 2018

Treatment and Prevention of Allergies

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By Ananya Mandal, MDReviewed by April Cashin-Garbutt, MA (Cantab)

Allergies or hypersensitivity of the immune system is a common disorder that affects almost one fourth of the whole population. The number of people who suffer from an over reactivity of their immune systems to relatively harmless substances is on the rise.

Treatment and prevention of allergies revolves around the theme that some allergic reactions may be life threatening and diagnosis and understanding of the risk of exposure is important. (1-4)

Types of treatment for allergies

Measures for treatment include allergy medications, decongestants and so forth.

Allergy medications

These drugs cannot cure the allergy but can prevent common symptoms of allergy like a runny nose and eyes, itching, sneezing etc.

A primary drug class used in allergies are Antihistamines. These antihistamines act by blocking the action of the chemical histamine that the mast cells release in response to an allergen.

This histamine is responsible for the symptoms of allergy like itching, sneezing, narrowing or constriction of the airways etc.

Antihistaminics may be taken as pills, gels, liquids, eye drops or nasal sprays. The eye drops are used in allergic conjunctivitis and the nasal sprays are used to reduce the swelling and watering of nasal mucus membranes in allergic rhinitis.

These agents, especially if taken as pills, often lead to increased drowsiness as a part of their side effects.

Decongestants

These are medications that are used to relieve a blocked nose that occurs in dust or animal allergy or in hay fever. They are available as pills, nasal sprays and also as liquids.

They lose efficacy over long term use and lead to side effects like drying of the nasal mucosa and drowsiness etc.

Steroid sprays

Steroids are drugs that modify the immune system. These steroid nasal sprays like Beclomethasone, Budesonide and Fluticasone act on the nasal lining and airways to reduce inflammation and congestion and reduce allergies.

Treating anaphylactic shock

For treatment of anaphylactic shock patient needs to be admitted immediately to the Emergency department as it could be life threatening.

After ensuring that the normal airway and oxygenation is maintained the patient is given adrenaline injections.

To prevent inadvertent anaphylaxis, patients are advised to wear a medical information bracelet or another form of identification that carries information about the risk of anaphylaxis.

Prevention of allergies

The main way to prevent an allergy is to avoid it. There are, however, other techniques too including Leukotriene receptor antagonists, steroid sprays and so forth.

Allergen avoidance

In as many cases as possible the potential allergen should be avoided. This means avoiding the allergy triggering food items like nuts, eggs, wheat, gluten, soya or milk etc.

This also means avoiding outdoors during the season of pollen dissemination in the environment, avoidance of pets and animal dander and keeping the house clean and free of dust and dust mites.

Common methods of allergen avoidance

Common methods of allergen avoidance include (1-4):

Avoidance of dust mites - These are tiny insects that breed in household dust. To reduce them wood or hard vinyl floor coverings should be preferred over woolly carpets. Cushions, soft toys and upholstery should be cleaned regularly by washing or vacuuming. Allergy prone individuals should use synthetic pillows and acrylic duvets rather that woollen blankets and cotton or down pillows.
Preventing pet allergies - Flakes of dead skin from pets are a reason for allergies. Pets should be avoided or should not be allowed within bed rooms and living areas. Grooming and washing regularly also helps.
Preventing mould allergies - Fungal spores grow in damp and decaying areas. Good and dry ventilation, dry and clean clothes storage in the wardrobes and removal of damps from the house helps prevent allergies from moulds.
Preventing food allergies - All manufacturers are instructed by law to clearly label any foods that may be known allergens like wheat, gluten, eggs, fish, milk, peanuts, nuts, soy beans, preservatives sulphur dioxide and sulphites etc. Persons with allergies are encouraged to inspect the labels carefully before consuming any food.
Preventing pollen allergies - Pollen allergies typically affect people during spring (for those allergic to tree pollen) and summer (for those allergic to grass pollen). Patients are advised to check weather reports for the pollen count and stay indoors if there are warnings of high pollen outside. Other ways to prevent allergies

Other important measures for prevention of allergies include:

Exclusive breast feeding for the first four months of life.
Living with parents who do not smoke.
Exposure to good probiotic bacteria in the infant diet.
Inclusion of vitamins C and E, and omega-3 polyunsaturated oils in diet.

Those living in farms and exposed to playing in dirt are also at a low risk of allergies.

Other ways to prevent allergies include leukotriene receptor antagonists and immunotherapy and so forth.

Leukotriene receptor antagonists

Drugs belonging to this class include Monteleukast and Zafirleukast. These block the allergic reaction triggered by the chemicals leukotrienes that are released during an allergy.

They are used to treat asthma. These agents do not relieve symptoms in an acute attack but may prevent future attacks.

Immunotherapy or hyposensitisation

This acts by introducing the allergen to the susceptible individual slowly in small doses. The body eventually becomes less sensitive to the allergen.

The allergen is usually injected under the skin of the upper arm. The injections are spaced at intervals of a week or less with slowly rising doses of the allergen.

The injections at their peak disease are given every few weeks for a year or two to blunt the sensitivity to the foreign protein. This therapy is used in severe hay fever or pet allergies. This therapy is performed under medical supervision.

Newer therapies to prevent allergies

Newer therapies in prevention of allergies include development of DNA vaccines, Anti-IgE antibodies that bind to the Immunoglobulin E and inactivate it (e.g. Omalizumab) and modification of the binding sites of the IgE.