Hay Fever and Allergic Rhinitis

Abstract

Rhinitis is an inflammatory condition of the nasal mucosa which causes nasal discharge, itching, sneezing, nasal stuffiness, congestion and blockage. Rhinitis can be due to a variety of causes and is classified as allergic, nonallergic and infective. This article focuses on the diagnosis and management of rhinitis with an allergic aetiology.

The GP curriculum and allergic rhinitis

The GP curriculum has several statements relating to rhinitis and allergy which are embedded in different sections of the curriculum including ENT & facial problems (15.4), Eye problems (15.5) and Respiratory problems (15.8).

GPs should be able to:

Manage infective and allergic rhinitis, sinusitis and nasal polyps

Manage conjunctivitis (infective and allergic)

Understand the current population trends in the prevalence of allergic and respiratory conditions in the community

Provide advice on avoidance of triggers and prophylaxis for allergic conditions

Explain the principles of treatment of allergic reactions and anaphylaxis

Trends in allergic rhinitis

Pollen is the most common cause of seasonal rhinitis in the UK and it is an increasingly common problem. In the 19th century Dr Charles Blackley wrote a thesis on hay fever and took several years to find seven cases, including himself. Today, the picture is very different and allergic rhinitis affects over 20% of the population.

Although allergies and atopic disorders do run in families and clearly have a genetic component, this rise in hay fever prevalence cannot be blamed on a sudden change in the gene pool. Rather, it must reflect the action of environmental factors on genetically susceptible individuals. Suggestions that air pollution may be responsible have largely been rejected as areas with heavy pollution, such as pre-1989 Eastern Europe, had much lower allergy prevalence than cleaner Western Europe. With the improved air quality post unification, hay fever levels in East Germany are catching up quickly with the rates in the West. These East: West comparisons suggest that factors associated with our prosperous western lifestyle are probably responsible. Among the two front runners are differences in exposure to infections or differences in diet. Both these factors are explained by the hygiene hypothesis.

The ‘hygiene hypothesis’ proposes that the recent rise in allergies is due to the loss of a protective effect from exposure to infections and environmental bacteria. Gut bacteria play a major role in shaping the developing immune system, and we know that the gut flora of westerners has changed in the past 40 years, possibly as the result of new food technologies and supermarket shopping. Early evidence suggests that restoring a pre-1960 gut flora may protect against allergy. Firstborn children are more likely to be allergic than their younger siblings, and it seems that the immune system of younger siblings may be directed away from becoming allergic by fighting off infections brought home by older siblings. Some of the best evidence to support this comes from farming communities. Children who grow up on farms in Austria are protected from becoming allergic, especially if they spend time with their mothers in the dirty environment of the cow byre in the first year of life. Taken together, these strands of evidence support the idea that microbial influences may be important, but it would be wrong to extrapolate from this to argue, as some have done, that we should abandon vaccination programmes or normal standards of personal hygiene!

Pathophysiology

Patients with allergic rhinitis are sensitized to specific allergens and have IgE antibodies for the relevant allergens bound to receptors on the surface of their mast cells. When they are exposed to the allergen, the allergenic proteins cross link adjacent IgE molecules and the mast cell degranulates. The mast cell releases the histamine it contains, as well as synthesizing other chemical mediators, including leukotrienes and prostaglandins. These mediators cause the immediate rhinitis symptoms of itching, sneezing, watery discharge and nasal congestion. Over the next few hours, a cellular inflammatory response occurs in which T-helper type 2 cytokines induce eosinophilic inflammation, which causes nasal blockage and nasal hyperreactivity (see Table 1 for allergic triggers).

Table 1.

Allergic triggers for rhinitis

Type of trigger	Examples	Comment
Pollens	Grasses, e.g. timothy grass, rye Trees, e.g. birch, hazel, alder, oak, plane Weeds, e.g. parietaria, ragweed	Pollens are the main cause of seasonal rhinitis
Mites	House dust mite	The allergens in the faecal pellets of house dust mites are the major cause of perennial rhinitis
Mites	Storage mites
Animals	Pets, e.g. cats, dogs, guinea pigs	The allergen is not the fur of the animals but rather the proteins in the saliva or sebaceous glands
	Horses
	Laboratory animals, e.g. rats, mice
Moulds	Alternaria	Moulds can cause seasonal or perennial symptoms
Moulds	Aspergillus

Diagnosing allergic rhinitis

As with all allergic disorders, the diagnosis of hay fever and allergic rhinitis is heavily dependent on a detailed history. Clinical examination is not particularly helpful in assessing whether symptoms are allergic in origin but may help to exclude other conditions. Having clarified the history, allergic sensitization can be assessed by skin tests, blood tests or direct challenges.

History

When taking a history to establish an atopic disorder, ask about the patient's belief about cause(s). Take a record of the patient's physical symptoms; listing these in order of priority for the patient helps focus medication choice.

Onset and course

The terms ‘seasonal’ and ‘perennial’ are used to distinguish between rhinitis with different triggers. Pollens and mould spores characteristically cause symptoms confined to one time of year, whereas house dust mite and pets cause problems throughout the year (Fig. 1). Symptoms at work suggest an occupational allergen and remission while on holiday would strengthen the possibility of an environmental cause.

Figure 1.

Seasonal allergen calendar.

Many people believe that they are allergic to oilseed rape or that it makes their hay fever worse. The bright yellow fields of flowering rape are a very visible feature of the British landscape each spring, with its characteristic cabbage-like smell. In general, plants with highly visible flowers are less likely to cause allergies than those with small insignificant flowers. Plants with gaudy flowers use insects to achieve pollination and have heavy sticky pollen grains that adhere to insects but do not travel far on the wind. Conversely, wind-pollinated plants have insignificant flowers because they do not need to attract insects. Agricultural workers do become sensitized to rape, but rape allergy is very rare among non-farmers. However, rhinitis and asthma patients are affected by the smell of rape, which causes non-specific irritation, like paint, perfume, petrol, etc.

Exacerbating and relieving factors are important. Ask about the efficacy of any lifestyle changes and treatments tried, how they were used and for how long.

Social history

A detailed social history facilitates assessment of allergen exposure (housing conditions, pets and occupation)

Personal and family history of atopy

A positive family history of rhinitis or asthma increases the likelihood that rhinitis is allergic. In the past few years, the link between rhinitis and asthma has been increasingly recognized in clinical and epidemiological studies. This link and the frequent coexistence of the two diseases are referred to as ‘united airways disease (UAD)’.

Drug history

A detailed drug history is vital as drugs such as alpha adrenergic blockers, angiotensin-converting enzyme (ACE) inhibitors, chlorpromazine, aspirin and non-steroidal anti-inflammatory drugs may cause rhinitis. Prolonged use of a nasal decongestant can cause rhinitis medicamentosa with chronic nasal blockage.

Impact on quality of life

While the symptoms of rhinitis are relatively trivial, their impact on patient's lives is significant. Rhinitis can reduce quality of life more than asthma. Rhinitis interferes with attendance at school and at work and has been shown to reduce performance at school. Research published in 2007 demonstrated a link between hay fever and exam performance; pupils who had hay fever symptoms on the day they took their GCSE exam were 40% more likely to drop a grade between their ‘mock’ and final examinations than those without hay fever (Walker et al., 2007). GPs are in a particularly strong position to help equip these students with the information that they need in order to optimize the management of their hay fever.

Presenting symptoms and differential diagnoses

In atopic rhinitis, the symptoms presented by the patient may include:

Sneezing

Itchy nose or palate—sometimes patients may also comment on itching in their external auditory canal

Rhinorrhoea

The appearance of the nasal secretion can give some hint of aetiology. If clear, infection is unlikely, yellow is suggestive of infection or allergy and green is usually infection. Should the patient present with blood tinged discharge, this is most likely to be due to a consequence of their rhinitis, nose picking or poor nasal spray technique. However, one should also consider and exclude tumour, foreign body, bleeding diathesis or a granulomatous disorder.

Nasal obstruction

Obstruction is characteristically bilateral in rhinitis. If unilateral, it is important to exclude the presence of foreign body, polyp or tumour. Patients may report that they have alternating nostril obstruction. What they are describing is the ‘nasal cycle’, the physiological congestion that is present in 80% of the population. This autonomic driven congestion alternates on average every 2 hours and may present as an isolated ‘symptom’ or in combination with pathological nasal obstruction.

Eye symptoms

Eye symptoms are associated with allergic rhinitis, particularly seasonal disease. The patient may report watering, redness, conjunctival (oedema) and itching. These symptoms are usually bilateral if allergic in origin and resolve within 24 hours if the allergen is removed.

Anosmia

A temporary loss of smell can be caused by a blocked nose. Anosmia is an unusual presentation of allergic rhinitis and polyps or more serious pathologies, such as intranasal tumour or intracranial mass, should be considered.

Clinical examination

History is key to diagnosis but one may sometimes see a horizontal crease across the dorsum of the nose which supports a diagnosis of allergic rhinitis. Examination is necessary to exclude differential diagnosis such as polyps or sinusitis rather than to confirm allergic rhinitis.

Investigation

The causative allergen can be confirmed by a blood test of specific immunoglobulin E or by skin prick test. Both tests must be interpreted in the light of the clinical history because patients may be sensitized without being allergic. To make a positive diagnosis of allergy requires both history and positive test, a positive test without supporting history is not diagnostic. Skin prick tests are suppressed by antihistamines and patients must refrain from using an antihistamine for 48 hours before testing.

Patient education

In the context of allergic rhinitis, there are three aspects of patient education to be addressed: the disease, pharmacotherapy and allergen avoidance. The patient organization, AllergyUK, is an excellent source of literature to reinforce the information given in the consultation (www.allergyuk.org). In a survey conducted in Wessex, one in four patients were using their medications as advised, so that there is plenty of scope to optimize use of existing therapy.

Allergic rhinitis

The patient, or parents of the affected child, should be informed about allergic rhinitis, its causes, mechanism and symptoms. It is important to explain that allergic rhinitis is a chronic disease and that the treatment prescribed is to minimize symptoms rather than to cure the disorder.

Rhinitis is a risk factor for the development of asthma. Rhinitis, eczema and asthma are all linked to allergy: many children start with atopic eczema in infancy, progress to rhinitis in childhood and become asthmatic in adolescence. This is sometimes called the ‘allergic march’ and raises interesting questions about whether having eczema increases the chance of becoming sensitized to pollen, and whether treating allergic rhinitis aggressively might reduce the risk of going on to develop asthma. In adults, occupational rhinitis often precedes the development of occupational asthma.

Drug treatment

Every patient should be given advice on the safety and potential side effects of their medication. If one is prescribing a nasal spray, it is important to demonstrate the correct technique (Fig. 2) as intuitively patients tend to do the opposite to what is required, tipping their head back and sniffing very hard. The correct procedure to maximize delivery to the nose is to put head down and direct the nozzle just inside the nose aiming at the outside wall while inhaling gently. If this technique of drug administration is difficult, the prescription of drops may be preferable.

Figure 2.

How to use a nasal spray.

Allergen avoidance

If an allergen has been identified, then it is appropriate, wherever possible, to exclude the exposure to the offending allergen. Grass pollen exposure may be reduced by staying indoors at times of peak pollen, i.e. mid morning and early evening, keeping windows closed when travelling in a car, not mowing the lawn and wearing wraparound sun glasses. Some patients benefit from applying Vaseline at the entrance of their nostrils as the greasy barrier reduces soreness and perhaps traps pollen grains. Monitoring the pollen forecasts enables patients to plan their days to avoid unnecessary high exposure.

For allergy to pets, the best avoidance is elimination of them from the household. This is not always welcome news to a family and one may have to compromise with exclusion of the pets from bedrooms and living rooms. Weekly washing of the cat or dog and grooming the dog outside can help. If a family does agree to get rid of their pet cat, they need to be warned that cat dander can persist for up to 6–12 months and therefore, symptomatic improvement will not be instantaneous.

House dust mites thrive in warm and humid rooms so the typical teenager's bedroom, with a non-aired bed, clutter and damp towels draped around provides a wonderful environment for them to thrive. Various regimes are recommended to reduce house dust mites including replacement of carpet with hard flooring (wood or vinyl), allergen proof mattress and pillow covers, washing bed linen at 60°C, removing clutter and frequent washing of soft toys.

For mould allergy, it is desirable to tackle sources of dampness in the home and reduce condensation. As well as structural alterations, it is helpful to avoid drying clothes indoors and close doors when cooking and showering to confine damp to kitchen and bathrooms.

Allergen avoidance is not easy and the clinical benefit may not always be of the magnitude desired because of the ubiquitous nature of many allergens. One should encourage patients to do what is feasible within their environment and budget.

Management of rhinitis

Despite allergen avoidance, patients with allergic rhinitis often continue to have symptoms. The type of symptoms and the severity of these symptoms should determine the medication recommended (Table 2).

Table 2.

Efficacy of different treatments for the different symptoms of allergic rhinitis (adapted from the BSACI guidelines for the management of allergic and non allergic rhinitis)

	Sneezing	Rhinorrhoea	Nasal obstruction	Nasal itch	Eye symptoms
H1 antihistamine
Oral	++	++	+	+++	++
Intranasal	++	++	+	++	0
Eye drops	0	0	0	0	+++
Corticosteroids
Intranasal	+++	+++	+++	++	++
Cromones
Intranasal	+	+	+	+	0
Eye drops	0	0	0	0	++
Decongestants
Intranasal	0	0	++++	0	0
Oral	0	0	+	0	0
Anti-cholinergics	0	++	0	0	0
Anti-leukotrienes	0	+	++	0	++

Oral H1 antihistamines

Oral antihistamines are the first-line therapy for mild to moderate allergic rhinitis. Antihistamines are effective in the reduction of symptoms and improvement in the quality of life. These drugs act predominantly on the symptoms of sneeze, rhinorrhoea and itch, i.e. the neurally mediated symptoms. Second-generation antihistamines have some, but not great impact on nasal blockage. Intranasal corticosteroids and intranasal decongestants are more efficacious for this symptom.

To derive maximum benefit from antihistamines, they are better taken regularly rather than as needed.

Topical intranasal corticosteroids

Nasal congestion is due to a combination of vascular dilatation, mucosal inflammation and tissue oedema. Some of this is driven by histamine, but several other cells and mediators are involved that are insensitive to antihistamines.

Intranasal corticosteroids act by suppressing inflammation at many points in the inflammatory cascade and therefore, they are superior to antihistamines in symptom suppression. In moderate and severe rhinitis, intranasal steroids are the drug of first choice. If itch and sneezing persist, add a nonsedating antihistamine, and if rhinorrhoea remains problematic, add ipratropium (Rinatec spray).

The onset of effect of topical intranasal corticosteroids is 6–8 hours after the first dose but clinical improvement may not be apparent for several days. It is preferable to begin treatment prior to the start of the relevant allergen season. For example, patients with hay fever should be advised to start taking topical intranasal steroids 2 weeks in advance of the expected start of the hay fever season.

Using a nasal spray causes nasal irritation, epistaxis or sore throat in about 1 in 10 users. These local adverse effects can be reduced by proper use of the nasal spray. The benzalkonium chloride used as a preservative in nasal sprays may irritate the nose of some individuals. Should this be the case, it is best to transfer the patient to Rhinocort nasal spray or Flixonase nasules.

Patients and parents frequently enquire about the advisability of steroid use. One can reassure them that, with products containing fluticasone or mometasone, systemic absorption is negligible. Absorption of betamethasone and dexamethasone is higher and therefore, these should be confined to short-term use only. There is no place for the use of intramuscular steroid injections in the management of rhinitis. If suppression of symptoms is paramount for a very special event (e.g. a wedding or examination), then a short course of oral steroids is preferable. For adults, the dose is 0.5 mg/kg orally for 5–10 days.

Ipratropium bromide

Ipratropium bromide is a topical anti-cholinergic and only decreases rhinorrhoea. It needs to be used three times a day and, because the symptom of rhinorrhoea is maximum in the earlier part of the day, it is suggested that the dosing is clustered in the morning.

Intranasal decongestants

While drugs such as ephedrine can be used briefly (under 10 days) for Eustachian tube dysfunction in infection or when flying, they have limited use in the management of allergic rhinitis. Intranasal decongestants are sometimes used to increase nasal patency before administering intranasal steroids.

Cromones

Sodium cromoglycate and nedocromil nasal spray do reduce nasal obstruction and are helpful for eye symptoms. Unfortunately, they have to be used three or four times each day. Therefore, their use is limited.

Anti-leukotrienes

Montelukast may be a helpful second-line drug in patients with allergic rhinitis and asthma. In the UK, montelukast is licensed for those with seasonal allergic rhinitis who also have concomitant asthma.

Specific immunotherapy

Specific injection immunotherapy (SIT) consists of a course of injections of allergen extracts, starting at a very low dose and escalating gradually over several weeks, followed by maintenance injections every 6 weeks for 2–3 years. SIT is effective in those patients with hay fever who are poorly responsive to standard drug therapy, but side effects can be serious and require careful assessment of risk: benefit ratios. Before 1986, many GPs gave SIT injections, but following a series of deaths in the 1970s and 1980s, SIT has been restricted to specialist centres and is generally reserved for patients who cannot be controlled by antihistamines and nasal steroids. Recently, alternative forms of immunotherapy, including sublingual drops and tablets, have made desensitization more accessible to patients with busy schedules or living a long way from an allergy centre.

Other treatments

Patients may ask about nasal douching. This is a treatment that is widely used in Europe but unfamiliar in the UK. Saline douches are available in high-street chemists and there is evidence from trials that they can reduce symptoms in adults and in children with seasonal rhinitis. It is a safe inexpensive treatment that can be used as an adjunct to conventional pharmacotherapy.

Alternative and complementary therapies remain popular, despite limited evidence that they are effective. An extract of the butterbur plant has been formally evaluated and is sometimes recommended because it has less side effects than an antihistamine. This herbal remedy is only safe if the plant has been subject to the process of extraction.

Allergic rhinitis in children

As in adults, the first-line treatments for children are antihistamines and nasal steroids. Some preparations are licensed for younger children than others. Parents should be made aware of the potential complications of allergic rhinitis, including sinusitis, otitis media and how to recognize these problems should they arise.

Management of rhinitis in the pregnant woman

Women with rhinitis may become pregnant and in addition, some women develop rhinitis in pregnancy. The pathogenesis of the latter is thought to be due to nasal vascular engorgement and placental growth hormone. Whatever the cause of rhinitis in pregnancy, the management is the same, but because most medications cross the placenta, it is advisable to consider the risks and benefits of prescribing. Treatment should be confined to the use of simple interventions, such as nasal douching and the prescription of drugs with a good track record. It is known from experience managing pregnant women with asthma that beclomethasone, fluticosone and budesonide are safe compounds. Chlorphenamine, loratadine and cetirizine may also be used but decongestants are not recommended.

When to seek a specialist assessment?

The vast majority of patients with allergic rhinitis can be managed in general practice. Referral to a specialist is indicated when there is

A suspected occupational aetiology for the rhinitis. There are over 300 agents that can give rise to occupational rhinitis. The early identification of the causative agent and avoidance can reduce the risk of progression to occupational asthma

A need for desensitization, e.g. seasonal pollen induced rhinitis where symptoms have responded inadequately to pharmacotherapy or pet allergy, where medical therapy is inadequate and the allergen is not easily avoidable (e.g. vets, district nurses)

Diagnostic uncertainty or concern about more serious aetiology

Key points

Allergic rhinitis is very common, affecting one in five individuals. It often precedes the onset of asthma (in the ‘allergic march’) and aggressive management of rhinitis may prevent the progression to asthma

Allergic rhinitis can have a significant impact on an individual's quality of life and on school performance and attendance; children with hay fever are 40% more likely to drop a grade between their mock GCSEs and final exam results

The mainstay of management for allergic rhinitis is allergy avoidance, antihistamines, nasal corticosteroids and patient education

Nasal sprays are frequently used incorrectly, technique should be reviewed on initiation of treatment and follow-up consultations

Specific immunotherapy is indicated for patients with seasonal pollen-induced rhinitis and pet allergy where medical therapy is inadequate and the allergen unavoidable, e.g. vets, district nurses

References

RCGP Curriculum statement 15.4: ENT and facial problems. Retrieved from www.rcgp-curriculum.org.uk/PDF/curr_15_4_ENT_and_facial_problems.pdf [date last accessed 10.01.2011].

RCGP Curriculum statement 15.5: Eye problems. Retrieved from www.rcgp-curriculum.org.uk/PDF/curr_15_5_Eye_problems.pdf [date last accessed 10.01.2011].

RCGP Curriculum statement 15.8: Respiratory problems. Retrieved from www.rcgp-curriculum.org.uk/PDF/curr_15_8_Respiratory_problems.pdf [date last accessed 10.01.2011].

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