Allergic Rhinitis is the most common atopic condition and one of the most common chronic conditions in children under 18 years of age. According to a global study carried out in the mid-1990s, its prevalence in children aged 6-7 years is as high as 15%, while in some countries it is as high as 40% in children aged 13-14 years. In childhood it is more common in boys. Children who have one or both parents with Allergic Rhinitis are more likely to develop Allergic Rhinitis as well.

Allergic Rhinitis is a chronic condition of the nose and is caused by the effects of airborne allergens. The most common allergens responsible are tree (e.g. olive) and plant (e.g. periwinkle, grass) pollen, dust mites, fungi found in moisture and animal (mainly cat and dog) epithelia. Dust mites, dust mites, fungi and animal epithelia are allergens that are in the air year-round, are called year-round and cause year- round Allergic Rhinitis. In contrast, tree and plant pollen is mostly circulating in the air at certain times of the year (the season of their respective pollen cycle) and therefore these allergens are called seasonal allergens and cause seasonal Allergic Rhinitis. Depending on its duration, Allergic Rhinitis can also be classified as intermittent and persistent.

The characteristic symptoms of a child with Allergic Rhinitis are runny nose (runny nose), congestion (congestion), sneezing and itching (itching) in the nose and/or inside the throat and/or ears. The intensity of the symptoms and their variation during the day may vary from child to child and from year to year.

As a result of congestion, the child often develops dark circles on the lower eyelids, breathes through the mouth, snores and has periods of apnea (breathlessness for a few seconds) during sleep. At the same time, because of the itching, he usually rubs his nose with a characteristic upward movement called "allergic greeting". In the long term, the 'allergic greeting' results in the development of a transverse fold in the nose corresponding to the point where the nose 'folds' when the child rubs it upwards.

The nasal discharge is usually clear (like water) or whitish and there may be a posterior nasal discharge, i.e. discharge running from the back of the nose down into the throat. The postnasal drip may be the reason why the child has a cough, especially when lying down.

The aforementioned symptoms are triggered when the child inhales allergens to which the child is allergic. However, a similar clinical picture may be seen when inhaling cigarette smoke, exhaust fumes, detergents, various strong smells (cologne, food being cooked), and when noticing differences in temperature or humidity from room to room. This reaction to non-specific stimuli is called non-specific nasal hyperresponsiveness and is due to the fact that chronic inflammation of the mucous membrane (the inside of the nose) has increased its "sensitivity" so that it cannot tolerate and overreacts to simple irritants that are not allergens. Therefore, non-specific irritants may exacerbate and cause flare-ups of Allergic Rhinitis.

Quite often Allergic Rhinitis coexists with Allergic Conjunctivitis (red eyes with itchy, watery eyes) and/or Allergic Asthma, as well as chronic sinusitis (e.g. sinusitis) and otitis media.

The first step in diagnosis is to acquire a detailed allergic history and review the inside of the nose. This is followed by skin prick tests on the most common allergens in the air of the area/country where the child lives. In the same direction, blood tests may be carried out to identify the specific antibodies (IgE) that the body may produce for each allergen. In the case of a positive result we say that the child is sensitized to the specific allergen. If the sensitizations match the clinical picture (e.g. the palm tree has symptoms only in spring and is sensitized to the olive tree, which is a tree that blooms in spring), then only the diagnosis of allergic rhinitis is given. In rare cases, a specific nasal challenge may need to be performed additionally. This is a test in which an extract of an allergen is placed in the nose to assess the reaction, i.e. the symptoms that may appear after a few minutes.

The management of the child with Allergic Rhinitis is multifaceted and consists of:

- informing and educating the parents and the child about the various parameters of the disease and its therapeutic approach,

- Avoidance of the responsible allergens,

- avoidance of non-specific irritants,

- administration of medication, and

- specific immunotherapy

Measures to avoid airborne allergens are not always feasible and when they can be applied their effectiveness is not always guaranteed. In any case, however, it is advisable to make efforts to apply them.

Medication is administered during periods when the levels of the allergen in the air are high and the young patient has symptoms. It consists mainly in the administration of an antihistamine (oral or nasal spray) and/or cortisone spray applied to the nose. Particularly effective is prophylactic medication, i.e. medication that precedes the onset of symptoms and is administered shortly before the period of increased allergen load in the atmosphere begins. It is mainly applied in seasonal allergic rhinitis.

And while drug treatment is simply symptomatic treatment, specific immunotherapy to airborne allergens is the sole causative treatment of Allergic Rhinitis. Its goal is to change the immune system to stop recognizing the air allergen as an enemy, stopping it from reacting when it comes into contact with it. This is why it is a long-term treatment that lasts 3-5 years. Immunotherapy is the only treatment that has been shown to halt the progression of Allergic Rhinitis to Asthma.

Olympia Tsilochristou
Allergy Specialist
PhD Candidate, University of Athens