Vasomotor rhinitis and allergic conjunctivitis
Vasomotor rhinitis and allergic conjunctivitis
Each month, Clinical Advisor makes one new clinical feature available ahead of print. Don't forget to take the poll and leave comments. The results will be published in the next month's issue.
Bronchiolitis is the most common lower respiratory tract infection that affects children in the first two years of life and the most common reason for hospitalization in this age group.1
Rhinitis — the inflammation of mucus membranes lining the nasal passages — is characterized by one or more of the following symptoms: nasal congestion, nasal pruritus, postnasal drip, rhinorrhea, and sneezing. These symptoms are frequently accompanied by itchy eyes, ears, and/or throat.1
Burden of disease
Allergic rhinitis is the sixth most prevalent chronic illness in the United States, affecting as many as 40 million adults and children every year.2
Worldwide, it is estimated that 10% to 30% of adults and up to 40% of children are diagnosed with allergic rhinitis, making it the most chronic pediatric condition.3
The prevalence of allergic rhinitis has increased substantially in recent decades in developed countries.4 However, only about 43% of affected patients have a pure allergic component to their rhinitis. Approximately 23 % have a nonallergic (vasomotor) rhinitis component, and 34% have a mixed component (both allergic and nonallergic).5
Because the therapy can be different for allergic and nonallergic rhinitis, providers must differentiate between the two. Nonallergic rhinitis is a broad classification of diseases that may be acute or chronic. Nonallergic rhinitis usually has an onset after age 20 years, unlike allergic rhinitis, which usually has an onset before age 20 years. Common symptoms of nonallergic rhinitis include nasal congestion, postnasal drip, rhinorrhea, and sneezing, with no allergic etiology. The differential diagnosis of rhinitis can include allergic, nonallergic and mixed rhinitis. These different forms of rhinitis can share a commonality of symptoms.
Screening for rhinitis leads to a more precise diagnosis. To help differentiate between the various forms, include a comprehensive history and physical exam along with information about patterns of disease, chronicitiy, seasonality, and magnitude of symptoms. Obtain detailed information about the presence of triggers or allergens in the home, school, workplace, or environment. Examples of potential irritants include paint fumes, tobacco smoke, perfume, car exhaust, cold or damp weather, alcoholic beverages, and spicy foods. Finally, ask when the symptoms first appeared.
Nonallergic rhinitis is the most common type and can be induced by a range of triggers, including changes in weather, ingestants, strong odors, and other environmental factors. Nonallergic rhinitis is a diagnosis of exclusion. The classification of nonallergic rhinitis syndromes includes several different types of disease (Table 1).
These types can be divided into known etiology and unknown etiology. The unknown etiology group can be further differentiated into eosinophilic and non-eosinophilic groups. The known etiology group can be subdivided into hormonal, medication, cholinergic, and anatomical types.
There are several ways to determine whether an individual's rhinitis is allergic or nonallergic, including a skin-prick test or a simple blood test.6 Many laboratories still use allergen-specific immunoglobulin E testing (commonly known as a radioallergosorbent test [RAST]). However, the RAST has been replaced by the more sensitive fluorescent enzyme-labeled assays, of which the ImmunoCAP is most common.7 All of these tests will help identify possible allergic triggers.
A simple questionnaire called a Patient Rhinitis Screen may be useful. This tool asks the patient about symptoms and what time of the year they occur. The questionnaire also asks about allergens and irritants that can cause rhinitis symptoms. An individual with only allergen triggers could indicate a pure allergic rhinitis; if only irritant triggers are noted, it could be nonallergic rhinitis; if both types of triggers are identified, a mixed type of rhinitis is the likely diagnosis.
The best treatment for rhinitis is allergen and/or irritant avoidance along with environmental controls. These non-pharmacotherapeutic options will work better for known and easily avoidable triggers. This treatment choice will work for such triggers as indoor pet dander, mold, dust mites, and cockroaches. However, it is very difficult to avoid such irritants as weather changes, strong odors, and environmental triggers, especially in the workplace or in large cities.
There are several pharmacotherapeutic options for allergic rhinitis, most commonly oral antihistamines, intranasal antihistamines, and intranasal corticosteroids. Other options include intranasal cromolyn sodium and subcutaneous specific immunotherapy (i.e., allergy shots).8