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towels, etc., to the opposite eye or other persons. It may
also be through contaminated eye drops.
Depending on the cause, conjunctivitis can vary in
severity from a mild hyperemia (redness) with tearing
to severe conjunctivitis with purulent drainage. The
conjunctiva is extremely sensitive to irritation and
inflammation.Symptomsofconjunctivitisincludeaforeign
body sensation, a scratching or burning sensation, itching,
and photophobia or light sensitivity. Severe pain suggests
corneal rather than conjunctival disease. A discharge, or
exudate, may be present. It is usually watery when the
conjunctivitis is caused by allergy, a foreign body, or viral
infection, andmucopurulent (mucusmixedwithpus) in the
presence of bacterial or fungal infection. Infectious forms
of conjunctivitis are usually bilateral, whereas unilateral
disease suggests sources of irritation such as foreign
bodies.
The diagnosis of conjunctivitis is based on history,
physical examination, and microscopic and culture
studies to identify the cause. Because a red eye may
be the sign of several eye conditions, it is important to
differentiate between redness caused by conjunctivitis,
which affects peripheral conjunctival blood vessels
(Fig. 38-4), and that caused by more serious eye
disorders, such as corneal lesions and acute glaucoma,
which affects blood vessels radiating around the edge
of the cornea. Conjunctivitis also produces only mild
discomfort compared with the moderate to severe
discomfort associated with corneal lesions or the severe
and deep pain associated with acute glaucoma.
Viral Conjunctivitis.
Adenoviruses are the most com-
mon causes of viral conjunctivitis.
3
The infection, which
is highly contagious, causes generalized conjunctival
hyperemia, copious tearing, and minimal exudate, and
is often accompanied by pharyngitis, fever, and malaise.
Viral conjunctivitis usually spreads through direct contact
with contaminated fingers, swimming pool water, or per-
sonal items. Children are affected more often than adults.
The disease usually lasts for at least 2 weeks and may
be complicated by visual symptoms due to epithelial and
subepithelial corneal involvement. There is no specific
treatment for this type of viral conjunctivitis. Preventive
measures include hygienic measures and avoiding shared
use of eyedroppers, eye makeup, goggles, and towels.
Persons who use contact lenses should wear wearing
them until the infection clears.
Bacterial Conjunctivitis.
Common agents of bacterial
conjunctivitis are staphylococci, streptococci (particularly
S. pneumoniae), Haemophilus
species,
Pseudomonas,
and
Moraxella.
The infection usually is characterized by
large amounts of yellow-green drainage. The eyelids are
sticky, and there may be excoriation of the lid margins.
Treatment measures include local application of antimi-
crobial agents. The disorder usually is self-limited, lasting
approximately 10 to 14 days if untreated and 1 to 3 days
if properly treated.
3
Gonorrheal conjunctivitis, usually acquired through
contact with genital secretions, is a severe, sight-threatening
ocular infection.
3–5
The symptoms, include conjunctival
redness and edema; lid swelling and tenderness; and
swollen preauricular lymph nodes. Treatment includes
systemic antimicrobial drugs supplemented with ocu-
lar antimicrobials. Because of the increasing prevalence
of penicillin-resistant
N. gonorrhoeae,
the choice of an
antimicrobial agent should be determined by current
information regarding antimicrobial sensitivity.
Chlamydial,
or
inclusion, conjunctivitis,
is usually
a benign, suppurative conjunctivitis transmitted by the
types of
Chlamydia trachomatis
(serotypes D through
K) that causes venereal infections
3–6
(see Chapter 41). It
is commonly spread by contact with genital secretions
and occurs in newborns of mothers with
C. trachomatis
infections of the birth canal.
3–6
It is usually treated with
appropriate oral antimicrobial agents.
Trachoma, a more serious form of infection, is caused
by a different strain of
C. trachomatis
(serotypes A, B,
and C).
6
This form of chlamydial infection affects the
conjunctiva and causes ulceration and scarring of the
cornea. It is the leading cause of preventable blindness in
the world, and is seen mostly in developing countries.
3,6
It is transmitted by direct human contact, contaminated
objects (fomites), and flies.
Allergic Conjunctivitis.
Allergic conjunctivitis encom-
passes a spectrum of conjunctival conditions usually
characterized by itching.
3–5,7
The most common of these
is seasonal allergic rhinoconjunctivitis, or hay fever.
Seasonal allergic conjunctivitis is an immunoglobulin
E (IgE)-mediated hypersensitivity reaction precipitated
by small air-borne allergens such as pollens.
7
It typically
causes bilateral tearing, itching, and redness of the eyes.
The treatment of seasonal allergic rhinoconjunctivitis
includes allergen avoidance and the use of cold
compresses and eye washes with tear substitute. Allergic
conjunctivitis also has been successfully treated with
topical mast cell stabilizers, histamine type 1 (H
1
)
receptor antagonists, and topical nonsteroidal anti-
inflammatory drugs.
7
Systemic antihistamines may be
useful in prolonged allergic conjunctivitis. In severe
cases, a short course of topical corticosteroids may be
required to afford symptomatic relief.
FIGURE 38-4.
Gonococcal conjunctivitis of right eye. Note
injection (redness) of the peripheral conjunctival blood vessels.
(From the Centers for Disease Control and Prevention Public
Health Images Library. No. 6784.)
