Respiratory allergy and hay fever: symptoms, causes, treatment
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Respiratory allergy is one of the most common chronic complaints today. Its best-known form is hay fever (allergic rhinitis), but allergy can also affect the lower airways and cause allergic asthma. In this article we explain what lies behind it, how to recognise it, and what treatment options there are.
What is an allergy?
An allergy is an overreaction of the immune system to substances that are harmless to most people. These are called allergens. An allergic body treats pollen, for example, as an "enemy" and starts an inflammatory reaction against it. In the process, histamine and other substances are released, and these cause the familiar symptoms.
The most common respiratory allergens
- Pollen: trees (hazel, alder, birch), grasses, weeds, and in Hungary especially ragweed,
- dust mites,
- animal hair and dander (cat, dog, horse),
- mould spores.
Why is it becoming more common?
The exact cause is unknown; several factors probably play a role together:
- Heredity: if the parents are allergic, the child is more likely to be as well.
- The "hygiene hypothesis": children who grow up in very clean environments encounter fewer microbes, and their immune system may be more prone to overreacting.
- Air pollution: smog and diesel soot irritate the mucous membranes and can intensify the allergic reaction.
- Climate change: longer pollen seasons and more pollen in the air.
Symptoms of hay fever
- runny or blocked nose,
- repeated sneezing,
- itchy nose, eyes and roof of the mouth,
- watery eyes, conjunctivitis,
- tiredness, poorer sleep.
Hay fever can be seasonal (caused by pollen, appearing only in certain months) or year-round (dust mites, animal dander, mould). The symptoms resemble a cold, but hay fever comes without fever, and the symptoms last for weeks or months.
Allergic asthma
If the allergic inflammation also affects the lower airways, breathing difficulty, wheezing, chest tightness and coughing may occur. Untreated hay fever increases the risk of developing asthma, so hay fever should not be taken lightly either. Read more about asthma in this article.
Allergy tests: what if the result is negative?
Allergies are most often diagnosed with a skin prick test (a small amount of allergen extract is introduced into the skin of the forearm) or a blood test (specific IgE levels). In small children, or when a skin test is not possible, a blood test is usually used.
Sometimes the symptoms clearly look allergic, yet the test is negative. There can be several reasons: the tested allergen panel did not include the trigger, the person took an antihistamine before the test, or the symptoms are caused not by allergy but, for example, by non-allergic rhinitis. In such cases it is worth doing the other type of test as well, or consulting an allergist.
How are respiratory allergies and hay fever treated?
Treating hay fever involves several steps, best put together with an allergist or GP:
- Avoiding the allergen: windows closed at night during pollen season, a shower and hair wash before bed, dust-mite-proof bedding covers, regular vacuuming with a HEPA filter.
- Medication: antihistamines, steroid nasal sprays, eye drops, as recommended by a doctor.
- Saltwater nasal rinsing: a well-documented, cheap and safe complement that washes pollen out of the nose.
- Allergen immunotherapy ("desensitisation"): the only treatment that can also influence the long-term course of the allergy. An allergist decides on it.
And salt therapy?
Many people with allergies also try a salt climate as a complement, because it offers a low-pollen, clean-air environment and a pleasant breathing sensation. What you can realistically expect is summarised in a separate article: Allergy and salt therapy: realistic expectations.
This article is for general information only and does not replace medical diagnosis or treatment. If you have allergy symptoms, see your GP or an allergist.