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Allergic rhinitis and allergic conjunctivitis are characterized by inflammation of the nasal mucosa, rhinorrhea, nasal congestion, sneezing, and conjunctival injection. The disorder is episodic, seasonal or perennial. Inhaled, ingested or injected allergens encounter IgE that is bound to mast cell membranes, resulting in mast cell degranulation.
Diagnosis
Allergic rhinitis presents with nasal congestion, rhinorrhea, sneezing, nasal or ocular pruritus, excessive lacrimation, and postnasal drip with resulting sore throat and cough. Patients may also have asthma or atopic dermatitis.
Physical examination
The conjunctivae may be injected, and profuse tearing may be present. Some patients present with swollen eyelids and boggy sclera. The nasal mucosa may be congested.
Patients may exhibit "allergic shiners" (darkened circles under the eyes)
Laboratory testing
Nasal smear. Infectious rhinitis demonstrates a predominance of neutrophils, and allergic disease shows a predominance of eosinophils.
Allergy testing is useful to identify patients with allergic disease that does not display.
Treatment
|
Second-Generation Antihistamines |
|
|
Drug |
Adult dose |
|
Cetirizine ( Zyrtec) Fexofenadine ( Allegra) Loratadine ( Claritin) Astemizole ( Hismanal) |
10 mg once daily 60 mg twice daily 10 mg once daily 10 mg once daily |
Serious cardiac side effects have been reported with use of astemizole (Hismanal).
Azelastine nasal spray ( Astelin) is an intranasal, topical antihistamine.
Intranasal steroids may be useful in relieving itching, rhinorrhea and congestion.
Ophthalmic therapy
Antihistamine-vasoconstrictor preparations. Vasocon-A ( naphazoline/ antazoline) and Naphcon-A (naphazoline/ pheniramine) are the most commonly prescribed antihistamine-decongestants.
Cromolyn ( Crolom), a mast cell stabilizer, is highly effective for the treatment of allergic conjunctivitis.
Lodoxamide ( Alomide), a mast cell stabilizer, is more potent than cromolyn; 1-2 drops qid.
Levocabastine ( Livostin) is a histamine H1 antagonist. It provides relief within a few minutes.
Ketorolac ( Acular) is a topical NSAID; 1 drop qid is effective for seasonal allergic conjunctivitis.
Topical ocular corticosteroids
Corticosteroids are very effective in treating ocular allergy. Dexamethasone ( Decadron) 0.1% ophthalmic soln, 1-2 drops q4-8h.
Because these drugs may elevate intraocular pressure and worsen infections, they should be administered.
Immunotherapy. Allergen immunotherapy is effective in patients with allergic rhinitis. Allergy treatment begins with identification of allergens, institution of avoidance procedures and administration of medication.