Hay fever:
symptoms and treatment of pollen allergy

In the case of an allergy, the immune system reacts disproportionately strongly to what are actually harmless, foreign substances. In a pollen allergy, the allergen is usually grass pollen. But the pollen from trees and herbs also makes life difficult for many people with allergies.

Pollen allergy – also known as pollinosis or allergic rhinitis – is the most common allergy in Western industrialised countries. In Switzerland, around 20% of the population suffers from it.

Pollinosis usually begins in childhood and occurs mainly during the pollen season in spring and summer. The resulting hay fever is therefore also called seasonal allergic rhinitis.

The main symptoms of a pollen allergy are:

• Sneezing
• Runny nose
• Congestion
• Watery, itchy eyes
• Itching in the palate, nose and ears

Some people may experience other symptoms such as:

• Cough
• Sore throat
• Headache
• Jaw pain
• Strong feeling of illness
• Increased temperature
• Sleep disorders

Another key characteristic of hay fever is nasal hyperreactivity. Non-allergic stimuli such as tobacco smoke, temperature changes or intense odours can also lead to colds and sneezing.

Unlike food or insect poison, pollen rarely triggers life-threatening allergic reactions. However, pollen allergy sufferers should still take their condition seriously. If hay fever remains untreated, it may progress, with about one third of cases developing into allergic asthma. Another common comorbid condition is atopic eczema (neurodermatitis).

The incidence of allergies is particularly high in Western industrialised countries. Researchers have not yet been able to fully explain why this is the case.

Allergies are diagnosed by a doctor qualified in allergology. The patient is first asked during a patient consultation (medical history) when symptoms occur, for example, and whether there are allergies in the family.

The doctor also examines the patient’s inner and outer nose and eyes and the surrounding skin.

Skin tests are the most important diagnostic tool for detecting a pollen allergy. The standard test is the prick test. The doctor drips an allergenic solution onto the skin and scratches it slightly. If skin reactions occur, this indicates an allergy.

An in vitro blood test can also help to detect specific IgE antibodies that are produced in people with pollen allergies. This test is the preferred option when a prick test is not possible (e.g. in infants and young children who cannot tolerate the multiple scratches involved in the prick test).

A nasal provocation test can confirm an unclear diagnosis. The suspected allergen is applied directly to the nasal mucosa and triggers a corresponding reaction in allergy sufferers.

The most important measure in the case of allergies is to avoid the allergenic substances. In the case of a pollen allergy, however, this is often very difficult. This is why medications are used to minimise symptoms.

Antihistamines (e.g. in the form of tablets, nasal sprays or eye drops) and anti-inflammatory glucocorticoids (“cortisone”) – usually as a nasal spray – are the first choice for children and adults with allergic rhinitis. The two medications can also be combined and are suitable for long-term treatment.

In addition, there are other possible measures that are effective for allergies:

• Leukotriene antagonists, administered alone or in combination with an antihistamine, can relieve colds and nasal congestion.
• Decongestives cause the swelling of nasal mucosa to subside. They should not be used for prolonged periods of time.
• Mast cell stabilisers (chromones) inhibit the release of pro-inflammatory messenger substances. They are administered, for example, in the form of eye drops or nasal sprays.

Desensitisation can cure pollen allergy

Hyposensitisation (desensitisation, specific immunotherapy) can be used to treat the cause of the pollen allergy. The immune system becomes accustomed to the allergen over an extended period of time, thus reducing its hypersensitivity.

Allergy sufferers should start specific immunotherapy as early as possible and continue for at least three years. It is suitable for children aged five and older.