PATHOPHYSIOLOGY
AR is an immunologic disorder that occurs in genetically susceptible individuals who produce allergen-specific IgE antibody responses after environmental exposures. The IgE-mediated response causes inflammation of the nasal mucosa. Compared to controls, individuals with AR demonstrate increased amounts of IgE antibodies in the nasal mucosa.11 IgE binds to basophils in the bloodstream and mast cells in tissue. Allergens then attach to IgE on basophils and mast cells, which release histamines, prostaglandins, cytokines, and leukotrienes, with histamine being the most significant mediator in the inflammatory response.
In response to allergy-provoking substances, patients experience immediate- and late-phase symptoms. Symptoms of each stage are similar, but congestion is the hallmark of the late phase. While both phases are clinically important because of their contribution to the patient’s symptoms, most patients experience continued exposure to allergens, resulting in constant, overlapping symptoms.
HISTORY AND PHYSICAL EXAMINATION
Patients with AR relate a history of congestion, excessive mucous production, itchy, watery eyes, bouts of sneezing, and more systemic symptoms, such as headache, malaise, and excessive fatigue. It is important to evaluate the degree and duration of the symptoms, noting patterns and triggers, in an effort to confirm the diagnosis and to help the patient evaluate treatment options.
When taking the patient history, always review the family history, which is often notable for allergies and other atopic diseases. Be sure to ask about medications and recreational drug use; a number of substances have been implicated in the development of rhinitis, including anticholinergic medications, oxymetazoline (when overused), and cocaine. Also, question the patient about self-medication and treatment to determine what may or may not have provided relief. Further questioning may also reveal a history of comorbidities, including contact dermatitis, asthma, eczema, and chronic sinusitis.
The physical examination of the patient with rhinitis begins with observation of the patient’s outward appearance, which may reveal allergic shiners (dark to purplish areas under the eyes), conjunctivitis, an allergic salute (a transverse crease of the nose caused by upward rubbing of an itchy nose), mouth breathing, and a generally tired appearance. The nasal turbinates are swollen and often pale. Mucous secretions are usually thin and clear. Enlarged tonsils and posterior nasal drainage may be visualized. The types of AR are listed in Table 1.
On the next page: Diagnosis and treatment >>