By Colin P. Kopes-Kerr, MD, MPH, JD, and Brian S. Alper, MD, MSPHDr. Kopes-Kerr is the medical editor of Primary Care Press and an editor for DynaMed. Dr. Alper is medical director of clinical reference products for EBSCO Publishing, Inc., in Ipswich, Mass., and www.dynamicmedical.com), a database of comprehensive updated summaries covering almost 2,000 clinical topics.

Description
• Ocular itching or burning, injected conjunctiva, often weeping; usually bilateral; associated with allergic history and often associated with other allergic symptoms

ICD-9 codes
• 372.0 acute conjunctivitis
— 372.00 acute conjunctivitis, unspecified
— 372.01 serous conjunctivitis, except viral
— 372.05 acute atopic conjunctivitis
• 372.1 chronic conjunctivitis
— 372.10 chronic conjunctivitis, unspecified
— 372.11 simple chronic conjunctivitis
— 372.14 other chronic allergic conjunctivitis

Prevalence
• 5%-22% of population has allergic conjunctivitis (more common in southern United States)

Causes and risk factors
• Usually inhalant (airborne) allergens, occasionally contact allergens
• Personal history of atopic or allergic disease, especially allergic rhinitis, seasonal allergies, and sensitivity to airborne allergens
• Family history of atopic or allergic disease

Associated conditions
• Vernal keratoconjunctivitis
• Atopic keratoconjunctivitis
• Allergic rhinitis
• Atopic dermatitis (eczema)
• Asthma
• Erythema multiforme
• Stevens-Johnson syndrome
• Allergic reaction to medication

Clinical presentation
• Red, itchy, watery eyes
• Eyelid swelling, periorbital swelling
• Absence of pain or photophobia
• Pharyngitis, sinusitis, and otitis media suggest allergy-related infections
• Symptoms may vary with
— Time (seasonal, perennial, monthly, diurnal, nocturnal)
— Geography (indoors, outdoors, school, work, home)
— Environment (pets, foods, soaps, fabrics, smoking)
• Family history of atopic disorders (asthma, rhinitis, eczema)

Physical exam
• Edema and redness of conjunctiva
• Confirm normal pupils, absence of mucopurulent discharge, corneal abnormalities, lymphoid hyperplasia of conjunctiva under the lids.
• Look for boggy mucous membranes, postnasal mucous discharge, cobblestoning (lymphoid hypertrophy of posterior pharynx).
• Review of systems findings
— Skin (dermatitis, eczema, urticaria)
— Ears (fullness, popping, infection)
— Nose (sneezing, pruritus, discharge)
— Throat (pruritus, scratchiness, soreness)
— Chest (cough, dyspnea, wheezing, sputum production)
— GI (diarrhea, malabsorption, food intolerance)

Rule out
• Infectious conjunctivitis (bacterial, viral)
• Vernal conjunctivitis
• Atopic keratoconjunctivitis
• Blepharoconjunctivitis
• Iritis

Testing
• Rarely necessary, but consider
— Immunoglobulin E testing
— Skin testing with histamine and saline controls
— Provocative (challenge) testing with presumed allergen
— Pulmonary function tests if cough or asthma is present

Treatment
• Cool compresses
• Instructions to stop rubbing
• Ocular medications(eyedrops)
—most FDA-approved in patients ≥3 years
— Waiting five minutes between drops recommended when two different drops used
— OTC decongestant-antihistamines have rapid but short-term efficacy and risk of rebound vasodilatation.
— Mast cell stabilizers (need several days to take effect)

  • Cromolyn 2%-4% (Crolom, Opticrom) one to two drops four to six times daily
  • Lodoxamide 0.1% (Alomide) one to two drops four times daily
  • Nedocromil 2% (Alocril) one to two drops four times daily
  • Pemirolast 0.1% (Alamast) one to two drops four times daily
    — Antihistamines
  • Emedastine 0.05% (Emadine) one drop four times daily
  • Topical antihistamines may be more effective than mast-cell stabilizers; emedastine may be more effective than levocabastine.
  • — Combination mast-cell stabilizers and antihistamines

  • Olopatadine 0.1% (Patanol) one drop twice daily
  • Azelastine 0.05% (Optivar) one drop twice daily
  • Ketotifen fumarate 0.025% (Zaditor) one drop every 8-12 hours
  • Epinastine 0.05% (Elestat) one drop twice daily
  • Combination mast-cell stabilizers and antihistamines appear marginally more effective than levocabastine
  • — Nonsteroidal anti-inflammatory drug (NSAID)

  • May be less effective
  • Ketorolac 0.5% (Acular) one drop four times daily; only NSAID approved for allergic conjunctivitis
  • Diclofenac eyedrops may be more effective than ketorolac eyedrops.
  • — Ocular steroids only in unusually severe or resistant cases

  • Long-term use may cause cataracts and increase intraocular pressure.
  • Loteprednol 0.2% (Alrex) one drop four times daily is approved for seasonal allergic conjunctivitis but contraindicated in ocular infections.

• Nasal or oral medications (nasal steroids, oral antihistamines, oral montelukast [Singulair]) may be considered if prominent allergic rhinitis.
• Oral antihistamines less effective than topical agents but combination may have added efficacy
• Some homeopathic preparations may be effective for relief of symptoms, e.g., Galphimia glauca.
• Ophthalmologic referral recommended when there is painful red eye, prominent light sensitivity, pupil irregularity or sluggish response to light, chronic case with vision impairment, fluorescein stain positive for ulcers, papillary conjunctival changes.