Toddler With Tearing and Sensitivity to Light
A 2-year-old girl with tearing and redness of her right eye for the past 2 to 3 days. Her parents stated that she occasionally rubbed her right eye and squinted in the sunlight. The child had been healthy and had no other acute concerns. Prior medical history was unremarkable, and review of systems was negative.
Visual acuity central, steady, and maintained in both eyes. On inspection, child appeared photophobic in the right eye—the eye would easily tear with ophthalmologic examination. Right temporal conjunctiva injected with a raised whitish lesion. Minimal clear, nonpurulent discharge. No eye pain or swelling of surrounding soft tissues. Remaining eye examination findings completely normal.
WHAT’S YOUR DIAGNOSIS?
Answer: Phlyctenulosis of the Conjunctiva
The word phlyctenule is derived from the Greek word phlyctaina meaning “blister.”1 Phlyctenulosis is a localized inflammation of the ocular surface characterized by subepithelial nodules of the conjunctiva and/or cornea with surrounding injection. The nodule can best be described as a minute subepithelial abscess.
Although the exact mechanisms are unknown, phlyctenules are presumed to be caused by a cell-mediated or delayed hypersensitivity response to bacterial cell walls.2 Early in the disease, neutrophils and lymphocytes are the responsible inflammatory cells; however, plasma and mast cells present later. In the past, this response was targeted to the tuberculin antigen in patients with latent tuberculosis; this is still found to be the case in developing countries in Asia and Africa.3,4
In developed countries, the most common cause is a delayed hypersensitivity reaction to Staphylococcus aureus cell wall antigens. Phlyctenulosis has also been associated with infection by helminths (especially Hymenolepis nana), Candida albicans, Coccidioides immitis, and Chlamydia and with lymphogranuloma venereum.5
Phlyctenulosis typically occurs in children and young adults and is one of the most common reasons for pediatric referrals to corneal specialists.6 Patients may present with photophobia, tearing, foreign body sensation, burning, itching, and blepharospasm.
Phlyctenular lesions may be unilateral or bilateral and occur near the limbus on the conjunctiva or the cornea. Corneal lesions usually cause more severe symptoms than conjunctival lesions and require aggressive treatment to prevent complications.
PHYSICAL FINDINGS AND POTENTIAL COMPLICATIONS
On examination, phlyctenular lesions appear as small, rounded, slightly raised, yellow or white nodules that are surrounded by dilated vessels. The lesions can soften, become necrotic, and ulcerate centrally. This can lead to complications, such as corneal scarring, thinning, and rarely perforation.7 Corneal lesions may migrate across the cornea, dragging a leash of blood vessels behind them (fascicular keratitis or wandering phlyctenule).8 This can result in scarring in the visual axis that ultimately leads to decreased vision.
Because of its clinical symptomatology, phlyctenulosis is frequently misdiagnosed as viral or allergic conjunctivitis, which often results in inappropriate treatment. Thus, referral to an ophthalmologist is necessary to confirm the diagnosis.
Most phlyctenular lesions spontaneously involute within 2 to 3 weeks leaving a triangular scar with its base at the limbus.2 The scar is an important diagnostic sign in cases in which the diagnosis is not obvious because it indicates previous episodes of phlyctenulosis.
Differential diagnoses include marginal infiltrates secondary to chronic blepharitis, inflamed pingueculum, infectious or sterile infiltrate/ulcer, and herpes simplex keratitis.6 When suspicion is high for tuberculosis (ie, patients without blepharitis, those at high risk for tuberculosis), a purified protein derivative test must be ordered.
Management of phlyctenulosis consists of a topical ophthalmic corticosteroid with concurrent antibiotic coverage for a short course. The use of corticosteroids, in conjunction with the antibiotic preparation, accelerates the rate of healing and decreases the risk of scarring.9 In severe cases, the disease may recur after discontinuation of the corticosteroids.
For recurrent or severe disease, oral doxycycline (100 mg twice a day) or tetracycline (250 mg 4 times a day) may be administered.10 However, this regimen is contraindicated in children younger than 8 years, pregnant women, and breast-feeding mothers because it can cause permanent tooth discoloration. Topical ophthalmic preparations of erythromycin or azithromycin may be substituted in these cases.
Topical cyclosporine A has been used in management of severe corticosteroid-dependent disease with promising results.11,12 Patients with associated staphylococcal blepharitis also require an eyelid hygiene regimen. This consists of lid scrubs (with dilute baby shampoo or commercially available lid scrub pads) 2 to 3 times a day to help reduce bacterial colonization along the lid margins and accumulation of sebaceous secretions. These patients should also receive preservative-free artificial tears for lubrication.
Frequent reevaluation, every few days to weekly, to document a clinical improvement is necessary. Resolution of the disease usually occurs within 10 to 14 days, in most cases. Once patients show significant improvement, the corticosteroid therapy can be slowly tapered; however, they must continue lid hygiene indefinitely.
Phlyctenulosis was strongly suspected in this patient. She was promptly referred to pediatric ophthalmology for evaluation, which confirmed the diagnosis. The child was treated with combination tobramycin and dexamethasone drops, applied 4 times a day in the right eye. She was monitored weekly for clinical response. The condition completely resolved without recurrence. The drops were tapered over the following weeks.