Conjunctivitis Beyond the Neonatal Period

Acknowledgment

The author acknowledges substantial use of material from previous editions by Avery Weiss.

Conjunctivitis is the most common infectious disease of the eye in childhood. It is useful to separate conjunctivitis into acute infection (abrupt onset, lasting less than 10–14 days) and chronic infection (insidious onset, often persisting for several weeks, months, or even years). Most cases of acute conjunctivitis are self-limited and can be managed by primary care providers. Evaluation and successful management of chronic conjunctivitis, however, usually require consultation with an ophthalmologist for specialized diagnostic techniques and to prevent eventual vision-threatening damage.

Microorganisms can be transmitted to the ocular surface in a number of ways, but direct contact with contaminated fingers is the most common. Bacterial pathogens usually are found in nasopharyngeal secretions as well. Viral pathogens have specific tissue tropism, some rarely affecting conjunctival mucosa (e.g., influenza, respiratory syncytial virus), with others having a proclivity for conjunctival mucosa (e.g., adenovirus, herpes simplex). Organisms can be inoculated into the conjunctiva by airborne droplets produced by coughing and sneezing and, because many viruses can remain viable on dry surfaces for several hours, infection can result from exposure to infected fomites. Vector-borne ocular infections occur in some developing countries. For example, the filarial parasite Onchocerca volvulus is transmitted to the eye by the bite of an infested blackfly.

Conjunctivitis is a clinical diagnosis based on the presence of conjunctival hyperemia and ocular discharge. Typically, the palpebral conjunctiva is more inflamed than the bulbar conjunctiva, and the area surrounding the cornea (limbus) is spared. Thus, pulling down the lower lid and noting the predominant area of inflammation enables one to distinguish conjunctivitis from keratitis, uveitis, and other causes of red eye. Conjunctival hyperemia associated with Kawasaki disease or bacterial toxin-mediated syndrome is distinguished by predominant involvement of bulbar conjunctivae and lack of exudate. The concurrent presence of a serous or purulent discharge confirms the diagnosis of conjunctivitis. Scant amounts of conjunctival discharge are best confirmed by asking the patient about the presence of eyelid crusting on awakening because dried exudate accumulates along the lid margins during sleep.

Acute Conjunctivitis

Bacteria and viruses cause acute conjunctivitis. An epidemiologic study of 847 children with conjunctivitis published in 2019 found that 63% of cases of acute conjunctivitis were caused by bacteria and 34% of cases by a virus. As many of the cases were diagnosed clinically, many cases of viral conjunctivitis may not have been included. Differentiating features of bacterial conjunctivitis and viral conjunctivitis are shown in Table 80.1 .

TABLE 80.1

Clinical Findings in Acute Bacterial and Viral Conjunctivitis

Data from Gigliotti F, Williams WT, Hayden FG, et al. Etiology of acute conjunctivitis in children. J Pediatr 1981;98:531–536; and Weiss A, Brinser JH, Nazar-Stewart V. Acute conjunctivitis in childhood. J Pediatr 1993;122:10–14.

Clinical Finding	Bacterial Disease	Viral Disease
Bilateral disease at onset	50%–74%	35%
Conjunctival response ^a	Papillary ^b or nonspecific	Follicular ^c
Conjunctival discharge	Mucopurulent	Watery
Conjunctival membrane	Late onset	Early onset
Preauricular adenopathy	No ^d	Yes
Concurrent otitis media	20%–73%	10%

a Conjunctival response refers to conjunctival appearance on slit-lamp examination.

b Papillary response denotes focal area of inflamed conjunctiva centered on a blood vessel.

c Follicular response represents focal accumulation of lymphocytes encircled by blood vessels.

d Except granulomatous bacterial infection.

Bacterial Causes

Haemophilus influenzae and Streptococcus pneumoniae

Nontypable Haemophilus influenzae , Streptococcus pneumoniae , and Moraxella catarrhalis are the most commonly isolated bacteria causing conjunctivitis. Collectively, these organisms are responsible for 55%–72% of acute bacterial infections of the conjunctivae. ^, An outbreak of 698 cases of acute conjunctivitis on a college campus in 2002 was caused by an atypical, unencapsulated strain of S. pneumoniae that was identical to strains that had caused outbreaks two decades previously.

Staphylococci

Staphylococcus aureus and S. epidermidis often are recovered from “eye” cultures but are infrequently a cause of acute conjunctivitis. Studies in which the lids and conjunctivae are sampled separately show that staphylococci can be recovered in relatively large numbers from lids, whereas few organisms are recovered from conjunctivae. Although staphylococci commonly colonize the lids without causing disease, they can cause blepharoconjunctivitis, a chronic infection of the lid margins.

Gram-Negative Bacilli

Gram-negative bacilli other than H. influenzae occasionally cause conjunctivitis. Special clinical circumstances usually are pertinent, such as (1) exposure to broad-spectrum antibiotics that promote the emergence of gram-negative flora; (2) poor hygiene in which children rub their eyes with fingers contaminated by feces or urine; and (3) prolonged hospitalization, especially in intensive care settings, where immobilization, exposure keratitis, and dragging of a tracheal suction catheter across the face raise the risk for direct inoculation.

Neisseria gonorrhoeae

Neisseria gonorrhoeae as a cause of neonatal conjunctivitis is discussed in Chapter 80 and is important to consider in all age groups because infection can lead to corneal ulceration and blindness. The organism binds avidly to surface receptors on the conjunctivae and cornea, triggering the release of bacterial toxins and inflammatory enzymes that damage the corneal epithelium and underlying collagenous stroma. Clinical hallmarks of infection are the onset of purulent conjunctivitis after an incubation period of less than 7 days and the presence of corneal opacification. Unusual cases of infection after incubation periods of up to 19 days and infection associated with minimal symptoms have been reported. Beyond the neonatal period, gonococcal conjunctivitis can result from sexual activity or abuse. N. gonorrhoeae can be isolated from the pharynx, rectum, or genital mucosa, as well as conjunctivae.

Neisseria meningitidis

Neisseria meningitidis , a rare cause of conjunctivitis, is important because it can be complicated by meningococcemia and meningitis. Systemic infection was more common among those treated with topical antibiotics alone. Bilateral hyperacute conjunctivitis is typical. Conjunctival scrapings show the presence of gram-negative intracellular diplococci.

Haemophilus aegyptius

Haemophilus aegyptius deserves special mention because it can cause a meningococcal-like illness. In South America, this organism is the cause of Brazilian purpuric fever. Especially prominent in children younger than 10 years, this catastrophic illness typically begins as hyperacute conjunctivitis, which is followed by fever within 3–5 days. Disseminated purpura, hypotensive shock, and death ensue within 48 hours. Molecular studies show that all isolates causing Brazilian purpura fever are related genetically. The genome of pathogenic H. aegyptius is larger than that of nonpathogenic strains. Frequent gene exchange between bacterial species has been shown to underlie this genetic addition. In the US, nontypable H. influenzae is associated with simple acute seasonal conjunctivitis. Because 20%–70% of children with conjunctivitis have concurrent otitis media, clinicians should evaluate for this condition and consider treatment for non-typable H. influenzae , a common cause of this condition

Viral Causes

Viral conjunctivitis has an acute onset, spreading from one eye to the other within a week, and the inflammation lasts 4 days to 2 weeks ( Fig. 80.1 ) Involvement of the second eye usually is less severe than the first affected eye, and this pattern helps distinguish viral from bacterial causes. Conjunctival discharge is watery, and slit-lamp examination shows follicular hyperplasia of conjunctivae. Inflammatory membranes over the conjunctival surface can develop. Lid swelling can be minimal or marked. Invasion of the corneal epithelium (punctate keratitis) is associated with pain and photophobia. Superficial keratitis usually is transient but can evolve into an immune-mediated stromal keratitis that reduces vision. Ipsilateral preauricular adenopathy is common. Acute follicular conjunctivitis can be caused by a number of viruses, with associated ocular and nonocular clinical manifestations ( Table 80.2 ).

FIGURE 80.1, Bilateral conjunctivitis due to adenovirus.

TABLE 80.2

Diagnostic Features of Acute Follicular Conjunctivitis

Modified from Dawson CR, Sheppard JD. Follicular conjunctivitis. In: Tasman W, Jaeger EA (eds). Duane’s Clinical Ophthalmology , vol 4. Philadelphia, Lippincott-Raven, 1991, pp. 1–26.

Clinical Syndrome	Etiologic Agent	Eyelid Lesions	Corneal Lesions	Nonocular Findings
Pharyngoconjunctival fever	Adenoviruses 3 and 7	None	Punctate epithelial keratitis	Fever, pharyngitis
Epidemic keratoconjunctivitis	Adenoviruses 8, 19, and 37	Lid swelling	Early: epithelial keratitis Late: subepithelial opacities	None
Herpetic keratoconjunctivitis	Herpes simplex virus	Vesicles	Punctate epithelial keratitis Dendritic keratitis	None
Acute hemorrhagic conjunctivitis	Enterovirus 70, coxsackievirus A24	None	Punctate epithelial keratitis	Neurologic sequelae Facial palsy Radiculomyelitis
Newcastle disease	Newcastle disease virus	None	Punctate epithelial keratitis	Usually occurs in poultry workers or veterinarians
Rubella, rubeola	Rubella and rubeola viruses	Skin exanthem	Punctate epithelial keratitis	Fever, diffuse exanthem, cough, rhinorrhea; occipital, postauricular adenopathy (rubella); Koplik spots (rubeola)

Adenovirus

Pharyngoconjunctival fever is characterized by the concurrent presence of fever, pharyngitis, and conjunctivitis. It is caused by adenovirus (serotypes 3 and 7) and usually affects children younger than 10 years. Although direct contact with airborne droplets is the usual mode of transmission, prolonged fecal excretion of the virus may be responsible for epidemics associated with swimming pools.

Epidemic keratoconjunctivitis is the most common ocular infection due to adenovirus (usually serotypes 8, 19, and 37) in older children. ^, Unassociated with fever or pharyngitis, conjunctivitis often is associated with corneal inflammation. Diffuse punctate lesions of epithelial keratitis evolve over 7–10 days into circumscribed subepithelial opacities that can impair vision and result in local discomfort for weeks to months. Resolution occurs without scarring. In young children, adenovirus conjunctivitis often causes ocular adnexal inflammation, eyelid edema, and erythema simulating periorbital cellulitis; an inflammatory pseudomembranous or palpebral conjunctivitis is distinctive. Direct contact with infected individuals is the usual mode of transmission, but indirect spread by common-use instruments, particularly those used by ophthalmologists, also can occur. Adenoviral conjunctivitis can be associated with an acute respiratory infection and demonstrates seasonal variation as most viral illnesses. Faden and colleagues reported an outbreak of adenovirus 30 disease in a neonatal nursery in which 6 infants with preexisting respiratory disease expired, and ophthalmologic procedures were the infectious source. ^,

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