Key learning points:
– Do not underestimate the impact of hay fever on a person’s quality of life at work or school and during summer outdoor leisure activities
– Nasal steroids should be started pre-seasonally and not sniffed into the nasal cavity
– Co-administration of non-sedating antihistamines will be required in moderate or severe hay fever
The strict definition of hayfever is allergic rhnitis to grass pollen but popular usage means that it encompasses tree and weed pollens. It is common and affects more than 20% of the UK population. It is caused by the seasonal exposure to airborne grass pollens that trigger allergic inflammation predominantly in the nose and eyes. Hay fever significantly reduces an individual’s quality of life, affecting both attendance and performance, both at school and at work.
Diagnosis
Hay fever is diagnosed clinically by a history of symptoms typically starting in early June and resolving in August. The nasal symptoms include itching, sneezing, blocking/congestion and running. Eye symptoms comprise intense itching, redness and swelling of the white of the eye, watering, lid swelling and in severe cases periorbital oedema that can be aggravated by eye rubbing. Itching of ears and palate occurs in certain individuals. Seasonal allergic asthma can be associated.
Questions to ask about symptoms
– Seasonality? Do they occur at the same time each year? Summer symptoms indicate allergy to grass pollens. Spring symptoms indicate allergy to tree pollens.
– Do they occur at home? This could be pet or house dust mite allergy. Do they occur at work? Suspect occupational allergens. On holiday? Remission suggests an environmental or allergic cause.
– Quality of nasal discharge. This should be clear, making infection unlikely.
– Is there nasal obstruction? It can be partial or complete.
– Does the discharge affect both nostrils? A unilateral discharge is uncommon in hay fever and requires further medical input.
– Does the discomfort affect both eyes? Unilateral conjunctivitis in hay fever is unusual.
Testing
The diagnosis can be confirmed by specific allergy tests (specific IgE to grass pollen). These are rarely done in primary care as treatment is not specific for a particular allergen.
Treatments
Allergen avoidance
Allergen avoidance is effective in hay fever – evidenced by sufferers being symptom free outside the pollen season. At a practical level, complete grass pollen avoidance is impossible. Interventions that may help to reduce symptoms during the pollen season include wearing sunglasses, nasal filters and applying balms and ointments to the nose. For the majority of hay fever sufferers, drug treatments are required.
Pharmacotherapy
Many hay fever sufferers choose an intranasal steroid preparation with an oral antihistamine. For a more severe disease the option of immunotherapy should also be considered. This approach is reasonable for allergic rhinitis to birch pollen (symptoms in springtime) and house dust mite (symptoms all year round).
Antihistamines
Antihistamines are available as oral, intranasal and ocular preparations. All demonstrate clinical efficacy. It is important to use a drug with the least adverse effect, especially in situations such as pregnancy.
First generation anti-histamines such as chlorphenamine (Piriton) act for a short duration (six hours) and are less useful because of sedative effects and cognitive impairment. These adverse effects can compound the already impaired driving skills and examination results that accompany hay fever.
Second-generation antihistamines are longer acting, largely non-sedating and hence preferred.
Oral H1- antihistamines
These are first-line therapy for mild to moderate hay fever but have only a modest effect on nasal congestion. Cetirizine and loratadine are useful and widely available. Fexofenadine is the least sedating oral antihistamine but is only available on prescription. Acrivastine must be taken three times a day but can be associated with more sedation.
Topical H1- antihistamines
Nasal –Azelastine nasal spray is the only available intranasal antihistamine in the UK and is available in combination with fluticasone (intranasal steroid) as Dymista. The latter combination has been shown to be useful in trials.
Ocular –Olopatadine eye drops are shown in studies to be a useful ocular antihistamine and should be used twice daily. They can be combined with an oral antihistamine and an intranasal steroid spray.
Corticosteroid therapy
Topical intranasal corticosteroids are the mainstay of anti-inflammatory interventions in hay fever. Unlike antihistamines, intranasal steroids reduce nasal congestion. Intranasal steroids reduce all symptoms of rhinitis by approximately 17% more than placebo, with a variable effect on associated allergic conjunctivitis. Meta-analysis shows that intranasal steroids are superior to oral antihistamines in all aspects of hay fever.1
Their onset of action is six to eight hours after the first dose but clinical improvement may not be apparent for several days, with maximal effect only revealed after two weeks of daily treatment. Starting treatment at least two weeks before the start of the hay fever season improves efficacy. Traditionally, steroid drops were sniffed into the nose but modern sprays produce a fine mist that should not be sniffed. Instead, the patient should mouth-breathe while spraying into their nostrils.
Systemic absorption is negligible with mometasone and fluticasone, and these preparations are favoured for children. Systemic absorption is modest for the remainder but high for betamethasone and dexamethasone. Long-term growth studies in children using fluticasone and mometasone have demonstrated reassuring safety data, unlike beclomethasone, which should be avoided long term.
There are no trials of oral steroid use in hay fever. Their use is rarely indicated in the management of hay fever except in individuals who have failed to respond to appropriately used combination therapy. This rescue therapy might be considered mid grass-pollen season, where desensitisation is being considered for post hay fever season, or when exams are being adversely affected. An appropriate dosing regimen would be prednisolone 20 mg daily for seven days, 15 mg daily for seven days and 10 mg daily for seven days – then the drug should be stopped. Gastro-protection with a proton pump inhibitor such as omeprazole can be considered alongside the steroid treatment.
Intramuscular steroid preparations such as depomedrone are not recommended as the risk-benefit profile is poor compared to other available treatments.2
Anti-leukotrienes
Monteleukast has a therapeutic profile similar to antihistamines, with efficacy comparable to loratadine in hay fever, but is less effective than topical nasal corticosteroids. The response is less consistent than that observed with antihistamines. Monteleukast reduces the mean daily rhinitis symptom scores by 5% more than placebo.
The combination of an anti-leukotriene plus an antihistamine has no advantage over either drug used alone and is no more effective than topical corticosteroid alone. Anti-leukotrienes may have a place in asthma patients with hay fever.
Chromones
Sodium cromoglycate and nedocromil sodium inhibit the degranulation of sensitized mast cells, inhibiting the release of inflammatory and allergic mediators. They work best prophylactically, that is before exposure. They are generally well tolerated (including in pregnancy) but side-effects include local irritation, taste disturbance and headache. Olopatadine eye drops are superior in clinical practice.
Intranasal decongestants
These are not recommended.
Immunotherapy for grass pollen allergy (desensitisation)
Allergen immunotherapy can improve symptoms, reduce medication requirements and improve quality of life.
Subcutaneous injection immunotherapy (SCIT)is effective for hay fever.3 SCIT requires weekly updosing followed by four to six weekly maintenance injections for three to five years. In view of the risk of systemic side-effects, SCIT should be given only in specialist clinics by trained personnel with immediate access to adrenaline and resuscitation facilities.
Sublingual immunotherapy (SLIT)has emerged as an effective and safe alternative for the treatment of seasonal allergic rhinitis with or without seasonal asthma due to grass pollen.4
Sublingual immunotherapy is well tolerated, with side-effects largely confined to local itching and swelling of the oral mucosa. After supervision of the first dose by the prescribing physician during a one-hour period of observation, SLIT is self-administered daily at home. SLIT has an excellent safety record, although there are rare case reports of systemic reactions. It is licensed in the UK and the treatment course is three years.
Immunotherapy is the only treatment that can modify the course of hay fever with long term remission following discontinuation.5 Subcutaneous immunotherapy in children with seasonal rhinitis reduces progression to asthma, an effect that persisted for 10 years in studies.6
Allergen immunotherapy within the UK is recommended in patients with a history of severe hay fever and objective confirmation of IgE sensitivity (skin prick test positive and/or elevated allergen-specific IgE to grass pollen). Hence patients whose symptoms persist despite maximal drug therapy (combinations of intranasal corticosteroid and antihistamine taken regularly) should be considered for desensitisation.
A choice of SCIT or SLIT is based largely on patient preference as there are no adequately powered head-to-head comparative trials.
Acupuncture
Acupuncture as an intervention for hay fever has been evaluated in relation to placebo (sham acupuncture) and medical treatment. Robust meta-analysis has not been possible given the limited number of studies that conform to the trial methodology, hence it is not possible to recommend acupuncture as an intervention in hay fever.
Antihistamines in pregnancy and breastfeeding
Pregnancy
It is best practice to avoid taking drugs in pregnancy. Pregnant women should be informed that no drug can be considered absolutely safe, and the benefits of keeping the mother healthy have to be balanced against the small risk to the fetus. The consequences of inadequately controlled disease should be discussed with the patient and documented in the case notes.
There is no evidence in humans that antihistamines cause birth defects, but animal studies using high doses of hydroxyzine and loratadine have led to embryotoxicity. The data sheets for cetirizine, desloratadine, and loratadine advise avoidance in pregnancy. Hydroxyzine is specifically contraindicated in early pregnancy.
However, there is considerable clinical experience with cetirizine and loratadine in pregnancy, with no increase in the rate of congenital abnormalities. Hence antihistamines should only be used if clearly needed and when the potential benefits outweigh the unknown risks to the fetus. Nasal steroid sprays do not affect the fetus.
Breastfeeding
Antihistamines should be used during lactation only when the clinical imperative outweighs the potential harm to the child. The lowest dose should be used for the shortest duration. Significant amounts of antihistamines are excreted in breast milk and, although they are not known to be harmful, avoidance is advised by most manufacturers if the patient is breastfeeding.
Chlorphenamine may cause drowsiness and poor feeding. Both loratadine and cetirizine appear safer with only low levels found in breast milk, and therefore, these drugs could be considered if required.
References
1. Weiner JM, Abramson MJ, Puy RM. Intranasal corticosteroids versus oral H1 receptor antagonists in allergic rhinitis: systematic review of randomised controlled trials. British Medical Journal 1998;317(7173):1624-9.
2. Nasser SM, Ewan PW. Lesson of the week: Depot corticosteroid treatment for hay fever causing avascular necrosis of both hips. British Medical Journal 2001;322(7302):1589-91.
3. Calderon MA, Alves B, Jacobson M, Hurwitz B, Sheikh A, Durham S. Allergen injection immunotherapy for seasonal allergic rhinitis. The Cochrane Database of Systematic Reviews 2007;(1):CD001936.
4. Canonica GW, Cox L, Pawankar R, Baena-Cagnani CE, Blaiss M, Bonini S, Bousquet J, Calderon M, Compalati E, Durham SR, van Wijk RG, Larenas-Linnemann D, Nelson H, Passalacqua G, Pfaar O, Rosario N, Ryan D, Rosenwasser L, Schmid-Grendelmeier P, Senna G, Valovirta E, Van BH, Vichyanond P, Wahn U, Yusuf O. Sublingual immunotherapy: World Allergy Organization position paper 2013 update. World Allergy Organization Journal 2014;7(1):6.
5. Durham SR, Emminger W, Kapp A, de Monchy JG, Rak S, Scadding GK, Wurtzen PA, Andersen JS, Tholstrup B, Riis B, Dahl R. SQ-standardized sublingual grass immunotherapy: confirmation of disease modification 2 years after 3 years of treatment in a randomized trial. Journal of Allergy and Clinical Immunology 2012;129(3):717-25.
6. Jacobsen L, Niggemann B, Dreborg S, Ferdousi HA, Halken S, Host A, Koivikko A, Norberg LA, Valovirta E, Wahn U, Moller C. Specific immunotherapy has long-term preventive effect of seasonal and perennial asthma: 10-year follow-up on the PAT study. Allergy 2007;62(8):943-8.
