Allergic conjunctivitis
Background
- Conjunctivitis due to exposure to an allergen
- Chronic allergic conjunctivitis is also called vernal conjunctivitis
Conjunctivitis Types
Clinical Features
- Itching
- Watery discharge
- Injected and edematous conjunctiva
- Papillae on inferior conjunctival fornix
- Red, swollen eyelids
Differential Diagnosis
Unilateral red eye
- Nontraumatic
- Acute angle-closure glaucoma^
- Anterior uveitis
- Conjunctivitis
- Corneal erosion
- Corneal ulcer^
- Endophthalmitis^
- Episcleritis
- Herpes zoster ophthalmicus
- Inflamed pinguecula
- Inflamed pterygium
- Keratoconjunctivitis
- Keratoconus
- Nontraumatic iritis
- Scleritis^
- Subconjunctival hemorrhage
- Orbital trauma
- Caustic keratoconjunctivitis^^
- Corneal abrasion, Corneal laceration
- Conjunctival hemorrhage
- Conjunctival laceration
- Globe rupture^
- Hemorrhagic chemosis
- Lens dislocation
- Ocular foreign body
- Posterior vitreous detachment
- Retinal detachment
- Retrobulbar hemorrhage
- Traumatic hyphema
- Traumatic iritis
- Traumatic mydriasis
- Traumatic optic neuropathy
- Vitreous detachment
- Vitreous hemorrhage
- Ultraviolet keratitis
^Emergent diagnoses
^^Critical diagnoses
Bilateral red eyes
- Painful
- Painless
Evaluation
Clinical diagnosis of conjunctivitis^
| Bacterial | Viral | Allergic | |
|---|---|---|---|
| Bilateral | 50% | 25% | Mostly |
| Discharge | Mucopurulent | Clear, Watery | Cobblestoning, none |
| Redness | Yes | Yes | Yes |
| Pruritis | Rarely | Rarely | Yes |
| Increased Likelihood | Presence of mucopurulent discharge; otitis media | Concomitant pharyngitis; an enlarged preauricular node; contact with another person with red eye | NA |
| Additional | Treatment: Antibiotics | Treatment: Hygiene | Seasonal |
Management
- Mild: avoid triggers, cool compresses for 15 minutes QID
- Moderate: Histamine-blocking drops (e.g. naphazoline/pheniramine 0.025%/0.3%, olopatadine, pemirolast, or ketotifen)
- Severe: refer to ophthalmology for possible steroid therapy
Disposition
- Discharge with ophthalmology follow-up