What is an allergy?

An allergy is a disorder of the immune system consisting in triggering an inappropriate or exaggerated immune response to a substance called allergen, which does not normally produce such reaction in most of the population. Allergy may occur against a variety of common environmental allergens, generally protein molecules from plants, animals, food or drugs. Only people allergic to these substances will respond by triggering an exaggerated immune reaction (allergic reaction) when in contact with them.

What causes allergies?

Any allergen can produce allergy symptoms by breathing, swallowing or touching. Those that enter the body through breathing, are found in the air and cause respiratory and eye allergies. The most important ones are the pollens from grass, shrubs and trees, dust mites, fungus spores and animal epithelia and dander. Other allergens enter the body through ingestion, it is food and medicines that cause food allergies. The most important ones are nuts, cow’s milk, eggs, fruits, fish and seafood.

How does allergy occur?

When an allergen enters the body of an allergic person, their immune system recognizes it as a foreign substance and responds by producing antibodies called IgE. This results in a series of defence mechanisms that lead to the release of chemical mediators such as histamine, which shows up together with the characteristic symptoms of allergic reactions.

What are the causes of an allergy?

Allergic reactions depend on several factors such as individual susceptibility (genetic predisposition), various environmental factors that determine the intensity of exposure (air pollution in cities, food or hygienic measures), the nature of one allergen and route of exposure to it (respiratory, skin or by ingestion).

What are the symptoms of allergies?

Depending on the type of allergen and route of entry to the body, different clinical manifestations or symptoms of an allergic reaction may occur. The most common are:

• Conjunctivitis: itching, tearing and eye redness.
• Rhinitis: nasal itching, sneezing fits, nasal congestion and runny nose.
• Bronchial Asthma: Cough with or without mucus, shortness of breath, wheezing, pain or pressure in the chest. It is an obstruction of bronchi.
• Atopic dermatitis: Intense itching, redness, rash located in areas of folds.

What are the diagnostic procedures?

There are two types, skin tests and provocation tests.

• Skin tests are based on reproducing the allergic inflammatory response in the skin. The most useful are three: prick test, intradermal test and patch test.
• The prick test (intraepidermal test) is the application on the skin surface of a small amount of a suspected allergen extract (usually a drop) on which a slight puncture is performed with a short tip lancet. The results are observed after about twenty minutes. A hypersensitivity reaction causes redness, itching and swelling around the skin puncture.

Allergy Treatment: Specific Immunotherapy (SIT)

Immunotherapy is any immunological treatment which acts on the immune system itself. For optimal treatment of allergic diseases it is recommended to avoid the allergen, patient education, pharmacotherapy and specific immunotherapy. Drug therapy is a palliative therapy, not curative, impinging on the symptoms and not on the cause of the disease. Allergen immunotherapy or allergy vaccination involves gradually administering increasing quantities of an allergen extract to an allergic subject in order to reduce or eliminate the symptoms caused by subsequent exposure to that allergen. As stated by the WHO (World Health Organization), SIT is the only treatment capable of decreasing the patient’s allergic response to the allergen and thus change the natural course of the allergic disease. It is the only thing that can prevent the development of asthma in patients with allergic rhinitis. The main objectives of immunological treatment are, in the short term to reduce the symptoms due to a decrease in the inflammatory response, and in the long term, to prevent the development of a persistent disease.

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SIT administration:

Specific immunotherapy is administered through various routes, the most common are parenteral administration via subcutaneous injections of allergens, and the sublingual route of administration, consisting of administering the allergen through the sublingual mucosa. In addition, there is the nasal route. In most cases, low doses are initially applied and continued with small increments until the maximum dose or maintenance dose.

Recommendations for the allergic patient

Patient allergic to mites:

Mites belong to the group of arachnids. They are invisible and are present in house dust and storage sites. House dust mites and their faeces are highly allergenic. The main species are the Dermatophagoides (D. pteronyssinus and D. farinae), they feed on human dead skin that is continually shed with peeling, so they are very abundant in mattresses and pillows. Other species of mites (Tyrophagus, Lepidoglyphus, Glycyphagus…) feed on organic waste, especially fungi, therefore they can be found in pantries, kitchens and the floor mainly.

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Recommendations:

• Daily ventilate the house and keep a dry low temperature, to do that it is convenient to use a dehumidifier in order to control humidity below 50% and favour air circulation. The temperature should not exceed 22°C.
• Minimize dust avoiding too much furniture and objects like stuffed animals and bookshelves. Remove carpets and rugs.
• Avoid accumulation of dust on curtains, upholstery and cushions.
• Clean dust with damp cloths and use a vacuum cleaner with a HEPA filter weekly, checking the filter frequently. Do not sweep. Clean in the morning with the windows open.
• Avoid animals or, if not possible, avoid the entrance to the rooms and wash them every fortnight.
• Frequently change bedsheets, blankets, mattress covers and pillows. Wash at 60°C weekly.
• Use mattresses, bedframes and pillows made with anti-mite materials like foam rubber or latex.
• Use slatted bedframes and mattresses with dust mite protection covers. Avoid heating by air.
• Store clothes in closed wardrobes and in plastic bags. Do not store wet clothes in the wardrobe or wear them if they have been stored unwashed for a long time.
• Remove wool blankets and down duvets.
• Vacuum car upholstery frequently and use air conditioning with an anti-mite filter.

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Patient allergic to pollens:

Pollens are the male reproductive structures of seed plants and they remain suspended in the air. They pollinate plants in the season where their flowers blossom but vary in intensity depending on the year. Weather conditions greatly influence the intensity and duration of pollination. Rain, cold and humid days decrease pollen concentrations, and wind and hot and sunny days increase them. There are pollen collectors in the air throughout the country, which have been significant for the elaboration of pollen calendars that provide valuable information about when they appear, maximum values, how long they last, etc. The main allergenic pollens come from grass, some shrubs and trees. Gramineae are wild or cultivated plants (cereals) of the Poaceae family. They pollinate in May and June but there may be small concentrations throughout the year. The bushes with most allergens are Salsola, Chenopodium and Parietaria. Pollination periods range from May to October. The most important tree from an allergenic point of view in Andalusia and Castile – La Mancha is the olive tree. In the Mediterranean region also cypresses and plane trees.

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Recommendations:

• Use humidifiers.
• Make nasal irrigations upon rising, noon and at bedtime.
• Know the time, frequency, place of pollination and pollen count of those that you are allergic to (pollen calendar) in order to avoid exposure.
• Close windows at night and from 5 to 10 h (emission of pollen) and from 19 to 22h (decrease as air cools down). Use air conditioning and vacuum cleaners with pollen filter weekly.
• When the weather is dry and sunny and in spring avoid trips to the country, gardens or parks.
• Protect your eyes with sunglasses.
• Travel by car with closed windows and use air conditioning with a pollen filter that will have to be renewed regularly.
• Do not mow the lawn or lie on it.
• Avoid hanging clothes outside to dry and change when returning home.
• Avoid irritants such as smoke, dust, sprays or insecticides.
• Go on vacation to pollen-free zones like the sea.

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Patient allergic to animals:

It is allergy to hair, dander and feathers mainly. Specifically to certain proteins that are released to the environment from animal dead skin, hair or even saliva or urine. When the carrier substance gets dry, proteins are volatilized and deposited on surfaces or remain suspended in the air. These allergens can remain in the environment for several months after the absence of the animal at home. In the case of dogs, the allergen is also present in the hair. In the case of horses, rodents and other mammals such as goats and cows, allergens are found primarily in the urine. In the case of cats, the allergen is a protein produced in the sebaceous glands and is found in the hair. This substance can be transported on clothes and shoes, so they can be in homes where no animals live.

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Recommendations:

• Avoid living with the animal.
• If symptoms are bearable and the person does not wish to get rid of the animal, the entrance to the bedrooms should be avoided closing the doors. Ensure their permanence in an area away from carpets, curtains and upholstered furniture.
• Wash the animal once or twice a week and daily brush it outside the home.
• Wash hands after touching the animal.
• Vacuum the home with HEPA filters. And use air purifiers.
• Brush garments regularly.

Frequently Asked Questions (FAQs)

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How can I get a vaccine?

Allergy vaccines must be prescribed by an allergist. With the prescription the patient orders it to Probelte Pharma through a pharmacy.

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What to do if I have had an adverse reaction to a vaccine?

It is always advisable to contact your allergist, especially if it is a generalized reaction, to assess the modification of the pattern of administration of the vaccine or treatment discontinuation.

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Can I take other medicines along with the administration of a vaccine?

Most medications, especially those indicated for allergies, have no incompatibility with the administration of the vaccine. However, beta-blocker drugs, used to treat heart attack, angina, blood pressure, hyperthyroidism tachycardia and essential tremor, among others, are a relative contraindication to the administration of Immunotherapy. If you think you might be taking any of these medications, consult your doctor.

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What happens if another vaccine has to be administered?

If the administration of two types of vaccines coincides, you should delay or bring forward the administration at least one week.

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Can a vaccine be administered with a fever?

In case of fever above 37.5°C treatment should be discontinued for the duration of the same. If you were undergoing maintenance treatment, then continue treatment following the dosing schedule where you were when you stopped it. In the case of initial treatment and having rested less than three days, act similarly, but if initial treatment has stopped for more than three days, you should contact the specialist for instructions on how to continue the treatment.

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What to do if I miss a dose of sublingual vaccine?

Continue treatment following the dosing schedule where you left it.

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How long does the treatment of allergen immunotherapy last?

Between 3 and 5 years, although from early treatment allergy symptoms can begin to reduce.

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Can a pregnant patient be vaccinated?

The recommendations of the Society of Allergy and Clinical Immunology and the European Academy of Allergy and Clinical Immunology regarding the administration of immunotherapy during pregnancy are:

• If you are pregnant and you are having a vaccine administered at maintenance phase which you are tolerating well, you can continue administration following the same established pattern.
• If you are pregnant and you are having a vaccine administered at initial phase or are about to begin with the administration of an allergy vaccine, you should discontinue administration or not start, as there is a greater likelihood of adverse reactions that may be harmful to the foetus. In any case, the pregnancy itself can lead your allergic disease out of control, so more frequent check-ups with your allergist are recommended.

When should the sublingual vaccine be administered?

It is best to administer the vaccine on an empty stomach. It should always be administered at the same time of day. What is very important is not to brush your teeth in a while after the sublingual vaccine is administered.