What is allergic rhinitis?

Allergic rhinitis is characterised by inflammation of the nasal mucosa, mediated by immunoglobulin E, after exposure to an allergen.

It may manifest alone or may be associated to other allergic diseases such as allergic conjunctivitis (allergic rhinoconjunctivitis).

The symptoms include nasal obstruction, sneezing or watery discharge, nasal congestion and/or nasal inching. They occur for two or more consecutive days and most days last for more than one hour. They may affect daily activities as well as sleep.

What are the causes?

House dust mites:

Small arthropods of the Arachnid class. More than 30,000 species have been described. According to their location, they are divided into two groups: house mites (found in house dust) and storage mites. The first group includes Dermatophagoides pteronyssinus and D. farinae, which are frequently found in homes in Europe, South America and Australia; the second type is found more often in North America and is the second most frequent type in Europe.


  • Grasses: Poaceae are the most frequent cause of allergy worldwide; this family includes close to 10,000 species.
  • Trees: they are less responsible. Species of the Oleaceae family (olea europea, Fraxinus, ligustrum) are some examples.
  • Bushes or weeds: Parietaria, Artemisia and Chenopodium.

Airborne fungi:

Aspergillus, Alternaria, etc…

Domestic animal epithelia:

Cats, dogs, horses, guinea pigs, mice.

Other types from professional use, such as flours or latex.

How is it diagnosed?

The allergy specialist is in charge of making a diagnosis based on medical history, specific skin tests and blood analyses (determination of specific IgE), among others.

How is it treated?

Environmental control measures

The first step for the allergic patient is to avoid contact with the allergen as much as possible. For example, using hypoallergenic linens, products against mites, pollen filters and cosmetic and pharmaceutical products without allergy-causing products. It has been shown that the more allergic the patient, the greater the benefits of environmental control.

Medicinal products

They are used to relieve the symptoms produced by rhinitis. Symptomatic treatment for episodes of exacerbation, including antihistamines in the form of nasal spray or tablets; topical, local and oral corticosteroids, etc. Medicines relieve symptoms but do not treat the cause of the disease, and therefore do not modify the evolution or progression of the allergic disease.


Immunotherapy (“allergy vaccines”) is the only treatment that may alter the natural course of the allergic disease, as cited by the World Health Organization (WHO). It consists in administering the allergen extract to the allergic patient in increasing doses with an aim to regulate the immune system.

The objective is to decrease symptoms in subsequent exposures to the allergen causing the allergy. Administration is generally given by subcutaneous or sublingual route, depending both on patient assessment and the medical specialist.

In addition to improving allergy symptoms, immunotherapy also decreases the amount of times medication must be taken in addition to treatment.

Duration of treatment is recommended between 3 and 5 years.