Allergy Medications

Using treatments as prescribed can show a huge change in a patient’s health, mood and development once the medication or treatment routine is working to control the symptoms.

Antihistamines

Antihistamines work by blocking the inflammatory effects of histamine, one of the major chemicals that the body releases when it comes into contact with an allergen to which you are sensitized. Antihistamines are probably the best known type of allergy medication, and most are readily available from a pharmacy without prescription. They can calm sneezing, itching, runny nose and hives. They come in tablets, liquids, melting tablets or nasal sprays. The newer, non-sedating and less-sedating antihistamines are safer than the older antihistamines, because they are less likely to cause drowsiness or sedation.

Leukotriene Antagonists

They are blocking the action of a group of chemicals, the leukotrienes, which constrict the muscles around the airways of the lungs. Like histamine, they are released during the allergic reaction mainly from cells in the body, mast cells, which are central to the triggering of the allergic reaction.

Bronchodilators

They work by relaxing the smooth muscle of the airways of the lung. Bronchodilators are used to relieve the chest tightness and wheezing which are the immediate symptoms of asthma. If you are suffering from occasional wheezing or chest tightness you can safely use bronchodilators as a single therapy. If the chest symptoms are prolonged, bronchodilators must be used in conjunction with an corticosteroid inhaler, which will treat the longer-term inflammation that underlies recurrent attacks of asthma.

Decongestants

Decongestants are constricting the blood vessels in the nose and can be given as a nasal spray, drops or as tablets to provide immediate relief of nasal blockage. They should not be used for more than 7 days as they can damage the tissues of the nose and cause worsening of symptoms.

Chromones

The drugs, cromolyn sodium (or cromolyn) and nedocromil, are commonly grouped together as chromones (also called cromoglycates). Cromoglycate works by blocking the responses of the cells that release the histamine during an allergic reaction, and can be a useful alternative to an antihistamine in preventing allergic reactions. However, this treatment only works if taken before contact with the allergen, and it can take a number of weeks for the effects of the treatment to be seen. Cromoglycate is mostly used in eye drops, and is most beneficial in this treatment since antihistamines do not always offer much relief from allergic eye symptoms.

Adrenaline

Adrenaline (epinephrine) is used to treat anaphylactic shock, where the sudden, high levels of histamine and other substances released during an allergic reaction cause the patient to have difficulty breathing, and can also cause loss of consciousness. It works by countering all the effects on the body of the sudden release into the bloodstream of histamine and the leukotrienes. This drug is the most effective treatment for the acute severe generalized allergic reaction known as “anaphylaxis” and it has saved many lives.

Anaphylactic shock can occur immediately after contact with an allergen, or up to a few hours later. Adrenaline is a hormone produced by the body that decreases swelling associated with an allergic reaction, relieves asthma symptoms, eases breathing, tightens blood vessels and stimulates the heart. Research has shown that the sooner adrenaline is given once an anaphylactic reaction has started, the better the health outcome for the patient. For this reason, people who are at risk of anaphylaxis are often prescribed a single unit for self-administration by injection or via an automatic injection device (for example Epipen, Jext or Anapen) which is triggered when pressed firmly against the skin. The preferred site for injection is into the muscle of the outside of the thigh. It is essential that these are always carried with the allergic individual and are available for use. Adrenaline auto-injectors look like pens and are prescribed according to the weight of the patient. Most children will be given a junior injector, but larger children and teenagers will be prescribed the adult version.

Once a dose of adrenaline has been given, an ambulance needs to be called and the patient should go to hospital so that any further reaction can be treated.

Corticosteroids

Corticosteroids are often called “steroids”. The steroids used for the treatment of allergies are almost identical to the natural hormone, cortisol, which is produced by the body’s adrenal glands. Medicinal corticosteroids work by preventing the body from making the chemical messengers (called cytokines) which are responsible for prolonging the immediate tissue inflammation that occurs after allergen exposure. Corticosteroids are thus used for treating the long-term inflammation experienced in chronic conditions such as asthma, allergic skin conditions, hay fever and perennial rhinitis.

They can be given by nasal spray for hay fever and perennial allergic rhinitis. They reduce swelling. Swelling causes a stuffy, runny and itchy nose. They also can be taken by inhalation, for asthma, and as creams or ointments for allergic skin conditions. To avoid side effects, these inhalers and sprays are formulated to work on the surface of the nose or lung, and to be poorly absorbed into the bloodstream. Some allergic responses involve a second, late phase reaction hours after the initial allergic reaction. This second stage of allergic reaction is caused by the immune system calling further immune cells to defend the body. These cells release chemicals that further aggravate the part of the body that is already irritated from the initial allergic reaction, and can also cause additional symptoms in other parts of the body. Corticosteroids, unlike antihistamines, can reduce the symptoms of these late phase reactions, by limiting the activity of the cells responsible for releasing further chemicals in the body. In this way steroids not only reduce inflammation, but they can also stop an ongoing chronic allergic inflammation.

Corticosteroids can be taken in tablet form to treat multiple manifestations of allergic disease, for example in a patient suffering from asthma, allergic rhinitis and eczema. The prescribing of corticosteroids in tablet form is reserved for severe allergic conditions.

A patient using steroids should be monitored carefully and receive regular check-ups.

Anti-IgE Treatment

The importance of immunoglobulin E (IgE) in atopic disorders such as asthma, allergic rhinitis, food allergies, and atopic dermatitis is well established. Elevation of total serum IgE is typically found in many atopic patients, and in predisposed individuals, allergen-specific IgE is produced. The IgE antibodies are the most common cause of the immune system reacting to an allergen and initiating an allergic response. Anti-IgE drugs are being designed to reduce sensitivity to inhaled or ingested allergens, especially in the control of moderate to severe allergic asthma, which does not respond to high doses of corticosteroids. They take the IgE antibodies out of circulation. The anti-IgE medication can allow some people to reduce, and even stop, their inhaled steroid treatments. Omalizumab was the first humanized monoclonal antibody against IgE launched in 2005. In the meantime there is a lot of experience with this drug that interestingly also works very well in chronic spontaneous urticaria.

Allergen Immunotherapy

Allergen immunotherapy, also known as desensitization or hypo-sensitization, is a medical treatment for some types of allergies. Discovered by Leonard Noon and John Freeman in 1911, allergen immunotherapy is the only medicine known to tackle not only the symptoms but also the causes of respiratory allergies. It is the only causal treatment that changes the immune system. It is useful for environmental allergies, allergies to insect bites, and asthma. Its benefit for food allergies is unclear and thus not recommended. Immunotherapy is contraindicated in patients with severe, unstable, or uncontrolled asthma.

Injection Allergen Immunotherapy – SCIT

Allergen immunotherapy involves the injection of increasing amounts of allergen under the skin until sensitivity to the allergen is decreased. Injections are first given weekly or two times a week and then monthly over a 3-5 year period. Allergy symptoms won’t stop overnight. They usually improve during the first year of treatment, but the most noticeable improvement often happens during the second year. By the third year, most people are desensitized to the allergens contained in the shots — and no longer have significant allergic reactions to those substances. After a few years of successful treatment, some people don’t have significant allergy problems even after allergy shots are stopped. Other people need ongoing shots to keep symptoms under control. This treatment is very effective for bee, wasp, yellow jacket, hornet and ant venom allergy and for allergy to certain inhalant allergens such as grass, weed and tree pollen. Injection immunotherapy may also be of benefit in the management of cat, dog, dust mite and mold allergy. This type of treatment is the only form of therapy for allergic disease that can strongly reduce the symptoms or can lead to complete resolution of symptoms without medications and, when administered to children, may prevent the development of further allergic disease. Because there is a risk of a severe allergic reaction happening immediately or shortly after injection, allergen immunotherapy must be administered in a medical office where there are appropriate medications and equipment available. Patients must remain under medical observation for 20 – 30 minutes after an immunotherapy injection in case an allergic reaction occurs. Side effects during treatment are usually local and mild and can usually be eliminated by adjusting the dosage. The benefits may last for years after treatment is stopped.

Sub-Lingual (Oral) Allergen Immunotherapy – SLIT

Sublingual immunotherapy (SLIT) is a newer form of immunotherapy. Instead of injecting an allergen under the skin, small doses are administered under the tongue for two minutes and then swallowed. There are two types of SLIT – tablets and drops – at the time available for grass pollen, house dust mite and ragweed. Sublingual allergen tablets (SLIT-tablets) – Allergen is formulated into a rapidly-dissolving tablet that is held under the tongue until completely dissolved. The tablets are self-administered, once daily. Sublingual liquid allergen extracts (SLIT-drops) – An aqueous or liquid extract of allergen, administered as drops, is also held under the tongue for a few minutes and then is swallowed. The allergen is taken up through the oral mucosa. Holding the extract under the tongue appears more efficient for delivery of active drug. Sublingual immunotherapy (SLIT)-tablet therapy is initiated with the first dose given under medical supervision, and then administration continues once daily and is self-administered by the patient or caregiver at home.

Allergy sufferers are often allergic to more than one allergen. Shots can provide relief for more than one allergen, while SLIT treatments are limited to a single allergen.

There are pros and cons of these different forms of treatment.

  • SLIT is safer, with fewer local and systemic allergic reactions than SCIT.
  • SLIT is more comfortable for patients, no needle.
  • SLIT is more convenient for patients and clinicians because therapy is self-administered by the patient or caregiver at home.
  • Therapy adherence of the patient is important. Patients who regularly miss doses may not have satisfactory results.
  • Patient education will be required to ensure that the therapy is carried out safely and effectively. Patients will require education about how to resume therapy after missed doses.

Ask your allergist or allergy specialized doctor, he can help you make good short- and long-term decisions.