AR.pdf

Rhinitis Background Rhinitis is simply inflammation of the nasal lining. It is characterized by rhinorrhea, nasal congestion, sneezing, and itching. Most cases that presenting community pharmacy will be a viral infection or allergic in origin. Th...

Rhinitis Background Rhinitis is simply inflammation of the nasal lining. It is characterized by rhinorrhea, nasal congestion, sneezing, and itching. Most cases that presenting community pharmacy will be a viral infection or allergic in origin. This section concentrates on the differentiation of allergic rhinitis (AR) from other causes. For AR, there are currently different classifications but the ARIA (Allergic Rhinitis and its Impact on Asthma) guidelines classify AR into intermittent and persistent categories, with both subdivided into mild or moderate–severe disease. The ARIA classification is based on the timing of the symptoms and is divided into intermittent (occurring on less than 4 days per week and less than 4 weeks at a time) or persistent (occurring on more than 4 days per week and more than 4 weeks at a time). Rhinitis can have a significant impact on quality of life, impairing performance at work and school and disrupting sleep. Prevalence and epidemiology AR is a global health problem that has dramatically increased over the last 20 years, with studies suggesting that the prevalence has at least doubled in that time. The UK has one of the highest levels of AR in the world, with estimates ranging from 10% to 25% of adults and as many as 40% of children affected. These figures might, however, represent an underestimate, because many people do not consult their doctor and choose to self- medicate. Seasonal intermittent allergic rhinitis (hay fever) commonly affects school-aged children, with 10% to 30% of the adolescent population suffering from the condition. The mean age of onset is 10 years; the incidence peaks between the ages of 13 and 19 years. Allergic rhinitis is a recognized risk factor for the development of asthma. Etiology AR is a mucosal reaction in response to allergen exposure. Initially, the patient must come into contact with an allergen; for intermittent AR, this is usually pollen or fungal spores. Pathophysiology The allergen lodges within the mucus blanket lining the nasal membranes, and activates immunoglobulin E (IgE) antibodies formed from previous allergen exposure on the surface of mast cells. Potent chemical mediators are released, primarily histamine, but also leukotrienes, kinins and prostaglandins, which exert their action via neural and vascular mechanisms. This immediate response to an allergen is known as the early phase allergic reaction and gives rise to nasal itch, rhinorrhea, sneezing and nasal congestion. A late-phase reaction then occurs 4 to 12 hours after allergen exposure, with nasal congestion as the main symptom. Also of importance is the phenomenon of nasal priming. ARIA classification OF AR Patients, after a period of continuous allergen exposure, may find that they experience the same level of severity in symptoms with lower levels of allergen exposure. Similarly, symptoms will be worse than previously experienced when levels of the allergen are the same. Table 2.12 highlights the main allergens responsible for AR Arriving at a differential diagnosis In the community pharmacy setting, most patients who present with rhinitis will be suffering from a cold or intermittent AR. Diagnosis is largely dependent on the patient having a family history of atopy, the presenting clinical symptoms, and when these worsen. Asking symptom specific questions will help the pharmacist establish a differential diagnosis Clinical features of intermittent allergic rhinitis The patient will experience a combination or all four of the classic rhinitis symptoms of 1.nasal itch 2. sneeze (especially paroxysmal), 3. watery rhinorrhea 4. nasal congestion. Bilateral symptoms typically develop within minutes following allergen exposure. In addition, the patient might also suffer from ocular irritation, giving rise to allergic conjunctivitis. The symptoms will occur intermittently (i.e., at times of pollen exposure) and tend to be worse in the morning and evening because pollen levels peak at this time, as they do when the weather is hot and humid. In terms of classifying symptoms as mild or moderate to severe (as per ARIA), the following criteria are used: Moderate to severe: one or more of the following are present: Sleep disturbance Impairment of daily activities, leisure, and/or sport Impairment of school or work Troublesome symptoms. If none of these symptoms are present, this is classified as mild. Conditions to eliminate Likely causes Persistent allergic rhinitis Persistent AR is much less common than intermittent AR. As its name suggests, the problem tends to be persistent and does not exhibit seasonality. In addition to not having a seasonal cause, there are a number of other clues to look for that aid in differentiation. Nasal congestion is much more common, which often leads to hyposmia (poor sense of smell), and ocular symptoms are uncommon. Additionally, persistent AR sufferers also tend to sneeze less frequently and experience more episodes of chronic sinusitis. The most common allergen causing persistent AR is the house dust mite but animal dander (particularly from cats, dogs and horses) are common causes of symptoms, so it is prudent to ask about any pets the patient may have. Infective rhinitis This is normally viral in origin and associated with the common cold. Symptoms are acute in onset. Nasal discharge tends to be more mucopurulent than in AR, and nasal itching is uncommon. Sneezing tends not to occur in paroxysms, and the condition resolves more quickly, whereas AR lasts for as long as the person is exposed to the allergen. Other symptoms, such as cough and sore throat, are much more prominent in infective rhinitis than in AR. Unlikely causes Nonallergic rhinitis (vasomotor rhinitis or intrinsic rhinitis) Nonallergic rhinitis is thought to be due to either an overactive parasympathetic nervous system response or hypoactive sympathetic nervous system response to irritants such as dry air, pollutants or strong odors. The symptoms can be similar to AR, but an allergy test will be negative. Itching and sneezing are less common, and patients might experience worsening nasal symptoms in response to climatic factors, such as a sudden change in temperature. Onset of symptoms tend to be after the age of 20 years. Rhinitis of pregnancy Nearly 10% of women will experience rhinitis during pregnancy that is unrelated to allergy (Namazy & Schatz, 2014). It is thought that this occurs because of hormonal changes; however, evidence is lacking (Wallace et al., 2008). It usually starts after the second month of the pregnancy and resolves spontaneously after childbirth. Nasal congestion is the prominent feature. Rhinitis medicamentosa and medicine-induced rhinitis Rhinitis medicamentosa is due to prolonged use of topical decongestants (>5–7 days), which causes rebound vasodilation of the nasal arterioles, leading to further nasal congestion. Although the exact pathophysiology is unclear, it is thought to be due to desensitization of the alpha adrenoceptors as a result of constant stimulation. A number of oral medications are implicated in causing rhinitis through other mechanisms, including ACE inhibitors, reserpine, alpha blockers (e.g., terazosin), sildenafil, chlorpromazine, oral contraceptives, aspirin and other NSAIDs. Nasal blockage In the absence of rhinorrhea, nasal itch and sneezing, it is possible that the problem is mechanical or anatomical. If the blockage is continuous and unilateral, this may relate to a deviated nasal septum in adults, which may develop or be a result of trauma. Referral is needed, and surgery is recommended. If the obstruction is bilateral, this may relate to nasal polyps in adults. Nasal obstruction is progressive and is often accompanied by hyposmia. Referral is needed for corticosteroids or surgery. Nasal foreign body A trapped foreign body in a nostril commonly occurs in young children, often without the parent’s knowledge. Within a matter of days of the foreign body being lodged, the patient experiences an offensive nasal discharge. Any unilateral discharge, particularly in a child, should be referred for nasal examination, because it is highly likely that a foreign body is responsible. Fig. 2.5 will aid in differentiating the different types of rhinitis. Evidence base for over-the-counter medication Before medication is started, it is clearly important to try and identify the causative allergen. If this can be achieved, measures to limit exposure to the allergen will be beneficial in reducing the symptoms experienced by the patient. This is more easily accomplished in persistent AR than in seasonal intermittent rhinitis. Non pharmacological treatment of AR Allergen avoidance Avoidance of pollen is almost impossible but, if the patient follows a few simple rules, exposure to pollen can be reduced. Patients may choose to stay indoors when pollen counts are high. Windows should be closed (when in the house and when travelling in cars) and wrap-around sunglasses may be worn. Air conditioning in cars fitted with a pollen filter is also beneficial. Patients should avoid walking in areas with the potential for high pollen exposure (e.g., grassy fields, parks, gardens), as well as areas such as city centers, because many intermittent allergy sufferers will have increased sensitivity to other irritants, such as car exhaust fumes and cigarette smoke.  The two main causative agents of persistent AR — house dust mites and animal dander can be more easily avoided. Pets, for example, can be excluded from certain parts of the house, such as living areas and bedrooms, and acaricidal sprays and strict bedroom cleaning regimens have been shown to be of some benefit in reducing rhinitis symptoms (Sheikh et al., 2010). Cleaning regimens should include regular washing of bedding and mattress covers with hot water (to try and kill the mites), replacing carpets with hard wood floors, minimizing soft furnishings, and avoiding drying clothes on radiators. Medications Pharmacists now possess a wide range of therapeutic options to treat AR, allowing the vast majority of sufferers to be appropriately managed in the pharmacy. Management of AR falls broadly into two categories, systemic and topical. Systemic therapy: Antihistamines Both sedating and nonsedating antihistamines are clinically effective in reducing the symptoms associated with AR. However, given the sedative effects of first-generation antihistamines, they should not be routinely recommended. Of the second-generation antihistamines, community pharmacists currently have a choice between acrivastine, cetirizine or loratadine. All are equally effective and are considered to be nonsedating, although they are not truly nonsedating and cause different levels of sedation. Loratadine has been shown to have the lowest affinity for histamine receptors in the brain. In comparison, cetirizine was 3.5 times more likely to cause sedation and acrivastine, 2.5 times more likely to cause sedation than loratadine. On this basis, loratadine would be the antihistamine of choice. Topical therapy To combat nasal congestion and ocular symptoms, a range of topically administered medications is available, including antihistamines, corticosteroids, mast cell stabilizers and decongestants. Intranasal medication: Corticosteroids Intranasal corticosteroids are the most effective overall treatment for AR — a number of clinical trials have confirmed their efficacy and they have demonstrated superiority to antihistamines in the treatment of allergic rhinitis for all nasal symptoms, and equivalence for ocular symptoms. There is little difference in efficacy between the intranasal corticosteroids, and clinical evidence does not support the use of one intranasal corticosteroid over another. They have a slow onset of action (12 hours), and maximum clinical efficacy can take up to 2 weeks. Patients who regularly suffer from nasal congestion associated with AR should be advised to commence therapy before exposure to the allergen to maximize symptom control. Decongestants Their place in therapy is probably best reserved when nasal congestion needs to be treated quickly and can provide symptom relief while corticosteroid therapy is initiated and has time to begin to exert its action. Intraocular medication 1. Mast cell stabilizers Sodium cromoglicate has proven efficacy and is significantly better than placebo (Lindsay- Miller, 1979). However, it does require dosing four times a day, and adherence might be a problem. Further, cromoglicate takes 4 to 6 weeks to reach maximal response; therefore, mast cell stabilizers alone only have a role when patients can predict the onset of the symptoms well in advance. 2.Antihistamines The only ocular antihistamine available OTC is antazoline. At best it should be used short term to avoid possible rebound conjunctivitis caused by xylometazoline, which has been well documented. 3.Sympathomimetics OTC ocular sympathomimetics are commonly used to control ocular redness and discomfort. There appear to be no significant differences between ocular decongestants on the basis of their vasoconstrictive effectiveness. Like nasal sympathomimetics, they should be restricted to short- term use (