Curated by Luigi Ferritto (1), Walter Ferritto (2) |
Definition and Epidemiology
Allergic rhinitis is a pathology frequently encountered, which consists in inflammation of the nasal mucosa caused by exposure to certain substances.
MECHANISM OF ACTION
Allergic rhinitis is caused by an antigen-antibody reaction, during which phlogistic mediators cause vasodilation.
In the United States alone, individuals suffering from allergic rhinitis are over 50 million, figures that make it the most common chronic disease of adults and children.
The prevalence - that is the total frequency of the world population affected by allergic rhinitis - is more than 10%.
These estimates, however, are probably underestimated, since the symptoms are underestimated both by the person who is affected and by the doctor himself.
Risk factors
Among the certain risk factors, we recognize environmental pollution, the presence of allergy cases in family history, asthma, early exposure to domestic allergens (for example mites and dandruff of animals), early weaning and finding of elevated immunoglobulin IgE values in the blood.
Above all, the subjects who are at risk:
- live in highly polluted areas
- they are familiar with allergies
- they were born during the pollen season.
Treatment
The pathology control measures are based on the removal from the allergen, although this objective is not easy to achieve, and on the pharmacological treatment aimed at limiting the activity of the histamine, mediator of the inflammation that underlies the process.
For this reason, in mild to moderate, intermittent and persistent allergic rhinitis, the latest generation antihistamines represent the first therapeutic option.
In recent times the chronobiology of rhinitis has been studied in depth, that is the research on the incidence of symptoms over the course of 24 hours. Several clinical studies show that the symptoms related to allergic rhinitis tend to be concentrated in the early hours of the day, following a well-defined circadian rhythm.
These observations have led to a more careful consideration of the therapeutic approach to pathology, with the development of treatment strategies that favor the control of allergic rhinitis during the morning hours. In particular, in adults it has been shown that drugs with a prolonged half-life, such as the active ingredient desloratadine, allow - even with a single daily administration - to effectively control the symptoms related to nasal obstruction, repeated sneezing and tearing.
The goal is achieved with a satisfactory safety profile, given that the new generation antihistamines do not induce those undesirable effects - in the first place sleepiness and increased appetite - which often penalized the "old" antihistamines.
To learn more: Rhinitis Treatment Medications (including allergy)
Classification and Symptoms
To learn more: Allergic Rhinitis Symptoms
Today allergic rhinitis is divided into intermittent, persistent, mild and moderate-severe. These terms are progressively replacing the old definitions of seasonal and perennial allergic rhinitis.
In particular:
- intermittent allergic rhinitis : symptoms present for less than four days a week or less than four weeks a year;
- persistent allergic rhinitis : symptoms present more than four days a week and for more than four weeks a year;
- mild allergic rhinitis : absence of related disorders, such as sleep problems and interference with school and professional life and with daily activities;
- Moderate to severe allergic rhinitis : sleep disturbances and / or interference with daily life.
On the clinical front, allergic rhinitis can present with symptoms of different intensity and duration. In general, the division of patients into blockers (to whom the nose often sticks ) and sneezer and runner (those who sneeze a lot and often run nose) is preferred, based on the predominant symptoms:
- in blockers there are almost exclusively nasal obstruction, phlegm and only occasionally sneezing.
- in sneezer and runner there are symptoms more easily connected to allergic rhinitis, such as sneezing, rhinorrhea, itching and nasal obstruction, often associated with conjunctivitis.
