Hay fever, or seasonal allergic rhinitis, is a condition in which the individual has become sensitised to pollens and spores.
It differs from perennial allergic rhinitis in that the allergens are only present at certain times of the year so symptoms tend to be restricted to those times.
Around a quarter of the population suffers from hay fever. The prevalence is increasing in western countries.
It is more common in atopic individuals. Some individuals have both perennial and seasonal rhinitis.
The characteristic symptoms of hay fever are pruritus of the nose, eyes and palate; rhinorrhoea; sneezing and redness/watering of the eyes. Patients may complain of nasal blockage and postnasal catarrh but these symptoms are more common in perennial rhinitis.
Other symptoms found include wheezing/worsening of asthma; reduced smell and taste; reduced hearing from Eustachian dysfunction; and headaches.
The hay fever season lasts from spring into autumn. The timing of peak symptoms may point to the likely allergen.
During the spring, tree pollen (birch and oak) predominates whereas grass pollen peaks in mid-summer. In late summer, weed pollens are produced and symptoms in the autumn suggest fungal spores.
The examination should look at the ears, nose, throat and eyes. Findings include oedematous nasal mucosa, which may be bluish or purple; nasal polyps; nasal obstruction; watery rhinorrhoea; bilateral conjunctival redness; and sometimes swollen eyelids.
In children, a transverse crease (nasal salute) may be present from rubbing the nose upwards.
Definitive diagnosis of hay fever is by testing for allergy to pollen or spores. This can be done using blood (RAST) testing, but skin-prick testing is safe, effective and less expensive.
Allergy testing can help patients when taking action to avoid allergens.
Oral antihistamines are a good first-line therapy. They are effective in reducing most of the symptoms of hay fever except nasal congestion.
There is little to choose between different antihistamines in terms of efficacy, but other characteristics may influence choice.
The older antihistamines (such as chlorpheniramine) are sedating so should be avoided if the patient is to drive or operate machinery.
Long-acting antihistamines (such as astemizole) may take several days to achieve full effect so are best not used as required.
Intranasal corticosteroids are the treatment of choice in moderate-to-severe hay fever and for those who fail to respond to antihistamines.
They do relieve nasal blockage. They need to be started at least two weeks before the pollen season and should be taken regularly.
Again there is little difference in efficacy but once-daily preparations may be more convenient for some patients.
Sodium cromoglicate and nedocromil are mast cell stabilisers that can be useful for patients with eye symptoms.
Ipratropium bromide treats rhinorrhoea but does not affect other symptoms. Nasal cromoglicate can be useful but is less effective than nasal steroids.
Antihistamine sprays are more effective than cromoglicate but less so than steroids.
Intramuscular corticosteroids may relieve symptoms throughout the hay fever season, however, it is now considered that the risk/benefit ratio contraindicate this treatment.
Short-term oral prednisolone (20mg for five days) is an alternative for critical times, like exams. Leukotriene antagonists have been shown to reduce symptoms in hay fever but are less effective than topical steroids for rhinitis. They are useful in concomitant asthma and rhinitis.
Referral for immunotherapy remains an option for patients with hay fever resistant to standard therapies.
In addition to desensitising injections, a sublingual standardised grass pollen extract for grass pollen sensitivity has just been launched. This is taken daily and must be started eight weeks before the grass pollen season. It reduces symptoms by around 30–40 per cent.
This may be the only treatment required in mild cases and
should be recommended as a baseline therapy in all patients.
- Listening out for the pollen forecast. On days with a high pollen count avoid going out, shut windows and do not dry washing outside.
- Avoid the peak pollen times of the day. Pollen is released
in the early morning (7am to 10am) and late afternoon (4pm to 7pm).
- Wear sunglasses when outside.
- Change clothes and wash hair after going out.
- Keep car windows closed and use air conditioning with recirculation of air, if possible.
- Be aware that pet fur may carry pollen.