Pediatric emergency medicine trisk 4045 4045

present with a red, painful, watery eye. The conjunctival injection is usually
sectoral. Presence of concomitant vesicular lesions in the eyelid region helps raise
concern for HSV infection, however skin lesions need not be present. Patients
with herpes zoster ophthalmicus experience pain, often followed by development
of vesicular lesions in the involved dermatome (i.e., ophthalmic division of
trigeminal nerve), which is commonly associated with significant lid swelling and
pain ( Fig. 123.9 ). Corneal involvement may occur 5 to 7 days after skin lesions
are seen.
Airborne or contact allergic conjunctivitis is characterized by hyperacute
conjunctival injection associated with watery tearing and a blister-like swelling of
the conjunctiva (chemosis) ( Fig. 123.10 ). Itching is often a prominent symptom.
The history may reveal recent exposure to an environmental allergen (e.g., cat
dander). Seasonal allergic conjunctivitis, a recurrent reaction to outdoor pollens,
typically has a less dramatic onset. Patients may have a history of atopy such as
allergic rhinitis, asthma, or eczema.
TABLE 123.1
DIFFERENTIAL DIAGNOSIS OF CONJUNCTIVITIS