Health professionals

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.

Contact allergens enter the body through the skin when touched and produce skin reactions. The most common ones are metals (especially nickel) and some topical medications. Other allergens capable of producing allergy are latex, parasites and venom from hymenoptera (bees and wasps).


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.
  • Contact dermatitis in the area of skin that has been in contact with the allergen: rash, itching, redness, burning sensation and sometimes appearance of small blisters and peeling may occur.
  • Hives: Red welts, itching and skin rash.
  • Angioedema: swelling of eyelids, lips or limbs
  • Anaphylaxis: Characterized by shortness of breath, malaise, hypotension, vomiting, diarrhoea, cramps, unconsciousness and may even cause death.
  • Food Allergies Symptoms: The most common are swelling and itching of the mouth, diarrhoea, abdominal cramps and vomiting, but reactions can be generalized when allergens are absorbed from the intestine end enter the blood. Rash, redness and generalized itchy skin, nasal congestion, itching, sneezing and watery eyes, bronchial asthma and even anaphylaxis may appear.

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.
  • Intradermal test involves administration in the superficial dermis of an allergen extract in aqueous dilution. With this test an immediate reading (before thirty minutes) and delayed (after 24 hours) can be performed, to catalogue sensitization depending on the outcome.
  • The patch test consists of the application on the skin of one or more agents responsible for skin reactions by contact, in order to confirm a delayed hypersensitivity response. The patch is maintained for forty-eight hours and the response is observed up to two days after its removal. It can also be done with medicines.
  • Provocation tests are to reproduce the symptoms of the shock organ by contacting the patient with the suspected allergen. Depending on the route of exposure these tests may be ocular, nasal, bronchial, oral or parenteral.

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.


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.

Adverse effects of SIT:

Like all medicines, SIT with allergens can have different adverse effects both systemic and local, especially in subcutaneous administration. Local reactions occur at the site of injection and are characterized by erythema, heat and swelling. The dosing regimen will not need to be modified, but if the reaction is greater than 5 cm in diameter, the specialist may modify the pattern. These local reactions can be divided into immediate reactions (occurring between 20 and 30 minutes after administration) and delayed (occurring after 30 minutes of administration). Systemic reactions are characterized by generalized symptoms. They can occur from 15 minutes to 6 hours after administration. These reactions can be moderated (including symptoms such as rhinoconjunctivitis, mild hives and sneezing) and can be treated with antihistamines, or severe (in which bronchospasm, dyspnoea, hives and or anaphylaxis appear). In these cases a treatment with epinephrine corticosteroids or antihistamines should be applied immediately. The EAACI (European Academy of Allergy and Clinical Immunology) divides adverse reactions in local and systemic and at the same time classifies each depending on whether they are immediate or delayed.


Vaccine Storage:

  • Collect the vaccine from the pharmacy as soon as the pharmacist will advise you of its reception.
  • Keep the vaccine in the refrigerator door, never in the freezer. Do not freeze the vaccine. Also avoid leaving the vaccine in extreme temperatures (above 30°C).
  • Always keep the vaccine in the package that the manufacturer laboratory provides, as it is where it is better protected from light and shock.
  • When going to your medical centre to get your dose administered: it is not necessary to keep the vaccine refrigerated as it is assumed that it will be out of the fridge for a short period of time.
  • Watch for the expiration date specified by the manufacturer. Do not have the vaccine administered if it has expired.

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.



  • 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.


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.



  • 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.


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.



  • 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.

Patient allergic to fungi:

Fungi are microscopic organisms that grow in damp places and reproduce by very allergenic spores. These can be carried for long distances by the wind. The concentration of spores increases with wet weather and sunny weather and wind favours their release. Air conditioning systems facilitate its dispersion. Spores develop in damaged and inert materials. They can be inside homes in humid and poorly ventilated areas such as bathrooms and sinks, pantries, kitchens and basements. They are also found in food such as bread, cheese and fruits and as stains on walls. They also exist outdoors. Humid environments such as lakes, forests and rivers are places for its development.



  • Fix water leaks that can cause moisture.
  • Keep showers and bath areas dry.
  • Do not use sponges.
  • Use dehumidifiers to keep humidity below 50%.
  • Air rooms. Open bathroom windows after showers.
  • Avoid using carpet in bathrooms and basements. Avoid also wallpapers and thick curtains.
  • Clean wet and mouldy surfaces with bleach.
  • • Do not clean with products that use steam. Clean dark, poorly ventilated and damp areas of the home frequently.
  • Avoid formation of moisture in walls and windows. Use fungicide paint.
  • Do not store wet clothes or shoes in wardrobes or in poorly ventilated areas.
  • Do not have houseplants.
  • Do not leave food out of the refrigerator and remove garbage often. Wash fruits and vegetables before consumption.
  • Prevent dust build-up.
  • Away from home avoid visits to damp, dark and poorly ventilated places such as warehouses or barns, and avoid field trips on wet and rainy days.
  • Do not move fallen leaves on the ground or walk in the country when it is windy.
  • Avoid swampy areas.


Patient allergic to venom from hymenoptera:

It is an allergy to insect venom from the bee, wasp or hornet that enters the body through their stings. If redness, itching and mild swelling appears at the site of the bite for a few hours this is a normal reaction, but if redness and swelling are extensive lasting several days, it is an exaggerated local reaction, besides there may be severe systemic reactions including anaphylactic shock.



  • Avoid activities in areas with flowers.
  • Avoid perfumes and cosmetics of intense smell and dark clothing, patterned or bright.
  • Always try to be covered with trousers and long sleeves.
  • Avoid going barefoot or in sandals.
  • Do not store garbage in not well-closed bags or leave food in the open air.
  • Avoid harvesting and fruit picking.
  • Avoid making sudden moves if a hymenopteran flies by.
  • In case of a bite, if the sting is visible (bee), remove it with tweezers.
  • Avoid pressure on the bite.
  • In case of local reaction cool with ice and apply cortisone cream and antihistamine.
  • In case of systemic reaction it is necessary to administer adrenaline so you should always carry it self-injectable.


Patient allergic to food and medicine:

The most common allergies appear in early childhood when incorporating solid foods into the diet. Before the first year of age an allergy to cow’s milk and egg may appear. Between one and two years to soy, cereals and fish, and from two years of age to fruits, vegetables, grains and nuts. In adults the foods producing allergy are fruits, nuts, vegetables, fish and seafood.



  • Read food labels and medicine excipients.
  • It is recommended to introduce dairy products after the first year of life in infant feeding, egg after two years and nuts and fish from the age of three.

Frequently Asked Questions (FAQs)


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.


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.


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.


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.


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.


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

Continue treatment following the dosing schedule where you left it.


How long does the treatment of allergen immunotherapy last?

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


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.

Can vaccines be consumed once they are expired?

Once the vaccine has expired (the month shown in the “Expiration Date” has passed) it should not be administered to a patient because there may have been a degradation of the active ingredient and therefore lost the potency needed to perform the expected therapeutic effect.


What if the cold chain of a vaccine breaks?

Thermolabile pharmaceutical specialties can be for a few hours or even days at room temperature without alterations of importance. Individualized allergy shots are stable at less than or equal to 30°C for a maximum period of 15 days. However, we recommend that our vaccines are not left outside the refrigerator (28°C) for extended periods of time.


What should be done if a vaccine is frozen?

Vaccines are biological products that lose their potency and therapeutic effect in case of freezing. Discard the vaccine and request it back to the lab through your pharmacy.


What to do in case of travelling with a vaccine?

If you have to travel for a few hours, the vaccine does not need to be refrigerated. Avoid direct sunlight or placing it in hot areas. If you travel by plane it is advisable to take the vaccine with you as hand luggage. Never put in checked luggage to avoid possible freezing in the cellar. Keep in the container provided by the laboratory. Never freeze the vaccine, and on arrival at the place of destination store it in a cool location.


What to do in case of loss, damage or breakage of any vaccine vial?

  • In either case you must reapply for the vial to the lab through your pharmacy in order to replace it. You should do this as soon as possible to avoid a long delay in the administration of the following doses.
  • If the specialist prescribes a maintenance therapy


When should you apply for the maintenance vaccine?

Order maintenance vaccine sufficiently in advance, you must consider that the order and subsequent reception of treatment takes time because it is individualized. Therefore you must request continuation of treatment before the end of the last vial.


Can allergy be cured?

According to the World Health Organization, immunotherapy is the only treatment that can alter the natural course of an allergy reducing or eliminating its symptoms.


Can early exposure to allergens protect against future allergies?

Exposing children to allergens boosts their immune system which will protect them from future allergies.


What advantage does specific immunotherapy have against other allergy treatments?

The vaccines modify the patient’s immune response to the allergens that cause the allergy symptoms. Medications such as antihistamines are intended to ease symptoms but do not act on the root causes.


Are allergy shots safe?

Currently they are very safe. The frequency of severe reactions in the case of injectable vaccines is one in 25,000 doses. In addition, more serious reactions can be effectively treated with adrenaline.


What recommendations must be taken into account the day of the administration of a subcutaneous vaccine?

On the same day of administration, you should avoid physical exercise, intense work, drinking alcohol or having heavy meals and hot baths.


The allergen vaccine, also known as allergen-specific immunotherapy, is the etiological treatment of certain diseases mediated by immunoglobulin E (IgE). It is usually conceived as a long-term therapeutic procedure in which an allergen extract is administered over a period of 3 to 5 years.


During the first phase, called induction or initiation, increasing doses of the extract are administered at regular intervals, until the optimal dose or the maximum tolerated dose is reached. During the next phase, or maintenance phase, the dose achieved during induction is administered from 2 to 8 weeks, for a recommended period 3 to 5 years.

It is widely demonstrated that allergen-specific immunotherapy is the only treatment that acts on the origin of the allergic disease itself and, therefore, has a high probability of cure in patients undergoing it.


The World Health Organisation defines that “the allergen vaccine is currently the only treatment capable of changing the course of an allergic disease” (World Health Organisation Position Paper 1997).



A good diagnosis of allergic sensitization is the first step to getting patients to improve their quality of life, either by allergen avoidance or proper treatment. It is very important to use well-characterized and standardized allergenic extracts, leading to an accurate interpretation of the results for a correct diagnosis.


At Probelte Pharma, the allergenic extracts are prepared for the diagnosis of allergic sensitization by skin tests (prick-test or intradermal) or by a provocation test of a specific organ, which is to show the clinical symptoms reported by the patient after allergen exposure. Provocation tests are used in specific cases where there is doubt in the diagnosis by skin testing as the patient is not free of risk. Diagnostic tests are to be performed exclusively by the specialist.


Skin tests



Provocation Tests



Probelte Pharma provides the specialists in their clinical practice with different treatments, such as Subcutaneous Immunotherapy (SCIT) or Sublingual Immunotherapy (SLIT).