Hayfever- Part 2
As total avoidance of triggers like pollen is impossible, medication is often needed to control symptoms.
Oral antihistamines are effective in relieving eye symptoms, running nose, sneezing and nasal irritation but have negligible effect on nasal congestion. Antihistamines are useful in patients with troublesome symptoms at multiple sites e.g. itching of roof of the mouth, throat or eyes.
First Generation Antihistamines. ("Sedative")
Sedation is the most common side effect of these drugs and may affect the patient’s ability to drive and operate machinery and concentrate. They should not be used in patients with prostatic hypertrophy or narrow angle glaucoma. Tolerance to their side effects may develop. Chlorpheniramine (Piriton®) is available over the counter in pharmacies.
Second Generation Antihistamines. ("Non- Sedative")
Examples include desloratadine (Neoclarityn®), fexofenadine (Telfast®), levocetirizine (Xyzal®), loratadine (Clarityn®) and cetirizine (Zirtek®, Cetrine®). They only require once daily dosage and are non-drowsy. Loratadine and cetirizine are available over the counter without prescription. The non-sedating antihistamines are fast acting, have no reported cardiac side effects, and are not affected by the presence of food in the stomach. However, loratidine is best avoided in elderly patients and patients with liver problems. Whelehans now provide Cetrine Allergy® (a non-drowsy antihistamine) in a cost-effective pack of 30 for €4.
Decongestants have a limited role in hay fever and should be reserved for periods of severe nasal congestion. Nasal decongestants sprays and drops such as Otrivine® should not be used for longer than three to five days due to rebound congestion making the problem worse.
Nasal drops and sprays reduce inflammation and swelling of the nasal mucosa and in normal dosage side effects are minimal. It is best to start treatment a few weeks before the season begins. All corticosteroids nasal sprays appear to have similar efficacy. Fluticasone (Nasofan®), beclomethasone (Nasobec®) and Mometasone (Nasonex®) are the most regularly used. The once daily dosage regimen of Nasofan® and Nasonex® is convenient. Side effects are mild and transient and consist of nasal irritation and stinging, dryness, sneezing, sore throat, nose bleeds and fungal overgrowth. Flixonase®, Beconase® and Rhinex® are over the counter in pharmacies.
Ipratropium bromide nasal spray (Rinatec®) may be prescribed where running nose is the predominant symptom. It does not relieve itching, sneezing or nasal blockage.
Azelastine (Rhinolast®) is a prescription only nasal antihistamine spray with a rapid onset of action. It may provide an effective and safe alternative to oral medications. Otrivine Antistin® eye drops are fast acting antihistamine eye drops available over the counter.
Immunotherapy is the use of allergen vaccines containing house dust mite, animal fur or extracts of grass or tree pollen. By gradually increasing the patient’s exposure to the allergen that causes the allergy, the patient becomes tolerant to it. Immunotherapy is only used in patients with severe symptoms and must be done by a specialist. Long term relief can be achieved. Grazex® is a grass pollen extract tablet available on prescription for patients who have failed to respond to other hayfever treatments. Grazex® must be started at least 4 months before pollen season and should be continued for up to 3 years.
Seasonal Vs Perennial Hayfever
Some people may have hayfever all year round. This is called perennial hayfever. Perennial allergic rhinitis is usually allergy to indoor allergens like dust mites and animal fur. Classic perennial allergic rhinitis is associated with nasal symptoms, which occur for more than two hours per day and for more than nine months of the year. In perennial allergic rhinitis, nasal congestion is common while itchy and streaming eyes is less frequent.