Pediatric emergency medicine trisk 1685 1685
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Allergic rhinitis is the most common manifestation of atopic disease in children
and results in significant direct and indirect health care costs. Peak incidence
occurs in childhood and affects up to 40% of children and adolescents. Although
allergic rhinitis is not life threatening, it dramatically impacts the quality of life of
affected children and leads to significant health care utilization and costs. Severe
nasal symptoms have been associated with poor school performance, and,
complications of untreated allergic rhinitis include sinusitis, acute asthma, sleep
disturbances, dyssomnia, and the effects of chronic mouth breathing.
Pathophysiology and Classification
Allergic rhinitis is caused by an IgE-mediated hypersensitivity response of nasal
mucosa to foreign allergens. Following sensitization to foreign antigens,
reexposure triggers an immediate hypersensitivity reaction. The early response is
characterized by mast cell activation and the release of biochemical mediators
including histamine, prostaglandins, and leukotrienes. These mediators cause
vasodilation, mucosal edema, rhinorrhea, stimulation of itch receptors, and cough.
Historically, allergic rhinitis has been categorized as seasonal or perennial.
Seasonal allergic rhinitis is commonly caused by exposure to tree pollens (early
spring), grass pollens (late spring and early summer), and ragweed or other weed
pollens (late summer and fall). Allergens responsible for perennial allergic
rhinitis include animal dander, house dust mites, and mold spores. Allergic
rhinitis is classified by symptom frequency and duration (intermittent <4 days per
week or for <4 weeks per year; persistent >4 days per week and >4 weeks per
year) as well as by severity (mild or severe based on whether symptoms interfere
with quality of life).
