Seasonal allergic rhinitis is one of the most common diseases among all people in the world. The symptoms of allergic rhinitis occur after an inflammatory response involving the release of histamine which is initiated by allergens being deposited on the nasal mucosa. Allergens responsible for seasonal allergic rhinitis include grass pollens, tree pollens and fungal mould spores. Symptoms of allergic rhinitis may start at any age, although its onset is more common in children and young adults. The condition often improves or resolves as the child gets older. There is frequently a family history of atopy in allergic rhinitis sufferers. Symptoms may start in Farvardin when tree pollens appear. People can suffer from what they think are mild cold symptoms for a long period, without knowing they have perennial rhinitis.

Drug therapy should be based on the patient’s age and condition. It would be useful to know if any medicines have been tried already to treat the symptoms, especially where there is a previous history of allergic rhinitis. In particular, the pharmacist should be aware of the potentiation of drowsiness by some antihistamines combined with other medicines. This can lead to increased danger in certain occupations and driving.

The severity of this disease is classified in two ways:

• Intermittent & Persistent

Intermittent: Occurs less than 4 days per week or for less than 4 weeks

Persistent: Occurs more than 4 days per week and for more than 4 weeks

• Mild & Moderate

Mild: All of the following – normal sleep; normal daily activities, sport, leisure; normal work and school; symptoms not troublesome

Moderate: One or more of the following – abnormal sleep; impairment of daily activities, sport, leisure; problems caused at work or school; troublesome symptoms

Symptoms

Rhinorrhoea

A runny nose is a commonly experienced symptom of allergic rhinitis. The discharge is often thin, clear and watery, but can change to a thicker, coloured, purulent one. This suggests a secondary infection, although the treatment for allergic rhinitis is not altered. There is no need for antibiotic treatment.

Nasal congestion and itching

Theinflammatoryresponsecausedbytheallergenproducesvasodilatation of the nasal blood vessels and so results in nasal congestion. Severe congestion may result in headache and occasionally earache.

In addition, nasal itching commonly occurs. Irritation is sometimes experienced on the roof of the mouth.

Eye symptoms

The eyes may be itchy and also watery; it is thought these symptoms are a result of tear duct congestion and also a direct effect of pollen grains being caught in the eye, setting off a local inflammatory response. People who suffer severe symptoms of allergic rhinitis may be hypersensitive to bright light (photophobic) and find that wearing dark glasses is helpful.

Sneezing

In some conditions the allergic response usually starts with symptoms of sneezing, then rhinorrhoea, progressing to nasal congestion. In this condition, symptoms are more severe in the morning and in the evening.

Referral is needed in these conditions:

1- tightness of the chest 2- wheezing 3- shortness of breath 4- coughing 5- earache 6-  sinusitis 7- no improvement is noted after 5 days of treatment

Treatment

1) Antihistamines

Many pharmacists would consider these drugs to be the first-line treatment for mild to moderate and intermittent symptoms of allergic rhinitis. They are effective in reducing sneezing and rhinorrhoea, less so in reducing nasal congestion. This drug category include diphenhydramine, clemastine, promethazine, chlorpheniramine, cetirizine, loratadine and fexofenadine. The order of these medications from high sedating to low and no sedating type is promethazine, diphenhydramine, chlorpheniramine, clemastine, cetirizine, loratadine and fexofenadine.

Side-effects

The major side-effect of the older antihistamines is their potential to cause drowsiness. Their anticholinergic activity may result in a dry mouth, blurred vision, constipation and urinary retention. At very high doses, antihistamines have CNS excitatory rather than depressive effects. Such effects seem to be more likely to occur in children.

Contraindication

Narrow- (closed-) angle glaucoma

Precaution

Liver disease or prostatic hypertrophy

Azelastine is also used in allergic rhinitis. Treatment should begin 2–3 weeks before the start of the hay fever season. Their place in treatment is likely to be for mild and intermittent symptoms.

2) Decongestants

Oral or topical decongestants may be used to reduce nasal congestion alone or in combination with an antihistamine. Topical decongestants can cause rebound congestion, especially with prolonged use. They should not be used for more than 1 week. Oral decongestants are included pseudoephedrine and phenylephrine. Nasal decongestants work by constricting the dilated blood vessels in the nasal mucosa.

Side effects

Stimulating effects on the central nervous system, Insomnia, an increase in blood pressure, an increase in blood glucose levels

Precaution

In people with diabetes, those with heart disease or hypertension, and those with hyperthyroidism

Drug interaction

MAOIs, tricyclic antidepressants, beta-blockers

3) Steroid nasal sprays

Beclometasone and fluticasone metered nasal spray can be used for the treatment of seasonal allergic rhinitis in patients over 18 years of age for up to 3 months. A steroid nasal spray is the treatment of choice for moderate to severe nasal symptoms that are continuous. Regular use is essential for full benefit to be obtained and treatment should be continued throughout the hay fever season.

Side effects

Dryness and irritation of the nose and throat, and nosebleeds

Contraindication

Glaucoma,pregnancy

4) Sodium cromoglicate

This drug can be effective as a prophylactic if used correctly. It should be started at least 1 week before the hay fever season is likely to begin and then used continuously. There seem to be no significant side-effects, although nasal irritation may occasionally occur.