What is hay fever?
Hay fever or allergic rhinoconjunctivitis, which is the medical description for the illness, is a condition affecting the upper airways. Allergy is an illness where the body’s immune system overreacts when exposed to an otherwise harmless substance (allergens). Under normal circumstances the immune system reacts when the body is infected with a pathogenic (harmful) virus or bacterium. However, allergies are mistakes in the immune system, and the body believes the harmless substance is dangerous and therefore attempts to get rid of it.
Hay fever can be divided into seasonal and chronic rhinitis. The illness can occur simultaneously with asthma, eczema, and sinus infection. In the UK 10-30 % of the adult population suffer from hay fever.
What are the symptoms?
The symptoms of hay fever appear when exposed to the allergen that the immune systems perceive as harmful. The immune response results in symptoms such as:
- Itchy nose
- Congested nose
- Frequent sinus infections
- Sneezing
- Runny nose
- Clogged ears
- Itchy, red, and watery eyes
- Tiredness
- General itching
- A feeling of pressure in the head
What are the causes of hay fever?
Hay fever is an allergic reaction, caused by an overreaction by the immune system to an otherwise harmless allergen. These allergens can be pollen from grasses (hay), trees, weeds, dust mites, airborne mushroom spores, and/or furred animals. There are many reasons why one develops hay fever; there is a genetic component and it might be caused by one’s parents smoking or polluted air. Therefore, the risk of developing allergies is increased if one’s parents and siblings have the illness.
The immune system is sensitive, because first contact with the allergen caused the immune system to produce IgE antibodies specific to the allergen. If the body is exposed to the allergen again, these antibodies with bind to the allergen and activate inflammatory cells that will attempt to eliminate the allergen. The body will attempt to remove the allergen by, for example, releasing histamine or stimulate the sneeze reflex, expelling the allergen from the airways.
When is my allergy at its worst?
Depending on the allergen you are susceptible to, your symptoms will manifest in certain seasons. If you are allergic to pollen from hazel, alder or elm, you should be cautious during spring. Allergy to grass pollen is worst during the summer period and mugwort/wormwood is worst late in summer. Some days can be worse than others. This is, among other things, because the pollen counts vary from day to day. Days with high temperature and clear skies, often have a higher count than cold and humid days. You can find a daily pollen forecast at https://www.metoffice.gov.uk/public/weather/pollen-forecast/.
How is hay fever diagnosed?
First and foremost, the physician will, based on your symptoms, suspect an allergy. Which type of allergy you suffer from can be determined by a certain test, called a scratch test. During the scratch test, the skin is exposed to different allergens. If you are allergic to one or more of these allergens, the affected area will turn red, swell, and start to itch.
What are the treatment options for hay fever?
If possible, avoid contact the allergen that triggers an allergic reaction. Additionally, there are different types of medications that ease the symptoms of hay fever. These include antihistamine, which is available in tablets, nasal spray, or eye drops. In severe cases it may be necessary to administer corticosteroid, either in tablets or nasal spray. However, due to the more severe side-effects of corticosteroids, this course of treatment is avoided when possible.
Furthermore, specific allergies can be cured by hyposensibilisation. This treatment requires that you receive injections under the skin, containing small amounts of the allergen, but with a gradually increasing dose over 8-15 weeks, followed by maintenance therapy every other month for 3-5 years. This allows the immune system to be accustomed to the allergen and establish a tolerance for the allergens presence. Thus, the immune system cease reacting to the allergen, and the symptoms disappear.
