Rhinitis and inhalant allergens
R. Naclerio and W. Solomon
Allergic rhinitis affects about 20% of the US population. The diagnosis is
based on patterns of symptoms, physical examination, and assessment of IgE
antibodies by skin or in vitro testing. The most common offending allergens
are pollens of grasses, trees, and weeds; fungi; animal allergens; and dust
mites. In an individual with nasal allergy, exposure leads to rapid release
of mast cell-derived mediators. This immediate response is followed by a
cell-dominated response, including eosinophils and lymphocytes. Cytokines
from T(H)2 lymphocytes, such as interleukin 4 and interleukin 5,
orchestrate allergic inflammation. Resulting tissue changes produce
symptoms of the disease and augment responses on subsequent exposure to
allergens and irritants. Strategies for avoiding offending agents are
important in management. In intermittent disease, antihistamines and/or
decongestants are first prescribed. More continuous symptoms may mandate
intranasal steroids. Immunotherapy is often helpful for patients who
respond poorly to pharmacotherapy and avoidance.
