There is a broad differential for the pediatric red eye, which may range from benign conditions to vision- and/or life-threatening conditions. This article presents a systematic differential, red flags for referral, and treatment options.
Key points
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If you have a visceral reaction when a child presents to your office with a red eye, take heart, because ophthalmologists do not like the chief complaint of “red eye” any more than you do.
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The red eye differential is broad, and if you do not treat or refer it correctly, it may walk back into your office days later with a vision-threatening problem.
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Many of the common causes of red eye are benign, but there are some dangerous diseases that should be recognized and referred.
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A thorough history is critical. Key questions include the onset, duration, unilateral versus bilateral, exposure to sick contacts, painful or itchy, discharge, and vision change.
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Refer if there is a significant change in vision, or severe photophobia and discomfort.
Etiology and contributory or risk factors
The red eye is complex because it is a nonspecific sign. A red eye may involve the conjunctiva; episclera; sclera; cornea; eyelid; nasolacrimal drainage system; or an internal ocular structure, such as the retina or uveal tract. The cause may be trauma, inflammation, infection, foreign body, or structural, and the cause may be localized to the eye or there may be an underlying systemic disorder.
The important thing to remember is that conjunctivitis may lead to blindness. A single episode of severe conjunctivitis can cause corneal scarring that could affect vision, or lead to conjunctival changes that become a chronic degenerative problem.
Etiology and contributory or risk factors
The red eye is complex because it is a nonspecific sign. A red eye may involve the conjunctiva; episclera; sclera; cornea; eyelid; nasolacrimal drainage system; or an internal ocular structure, such as the retina or uveal tract. The cause may be trauma, inflammation, infection, foreign body, or structural, and the cause may be localized to the eye or there may be an underlying systemic disorder.
The important thing to remember is that conjunctivitis may lead to blindness. A single episode of severe conjunctivitis can cause corneal scarring that could affect vision, or lead to conjunctival changes that become a chronic degenerative problem.
Tools to evaluate the red eye
The pediatrician has the essential tools readily available to assess a red eye and determine a treatment path, or make the decision to refer. An essential first step is to put on examining gloves to prevent an epidemic of viral conjunctivitis. Checking the vision should be done immediately, because when there is decreased vision, regardless of the other physical findings, it is imperative to refer. There might be posterior involvement of the retina or choroid that is causing the eye to be red from inflammation. A dilated examination is necessary to make the diagnosis.
A penlight or direct ophthalmoscope aids in assessing the pupils, looking for corneal clarity, and observing the pattern of redness on the conjunctiva and/or sclera. Intense redness at the limbus, referred to as ciliary flush, is often more concerning than mild general redness because it usually signifies problems on the cornea or inside the eye. The eyelids should be lifted and pulled back to get a view of the entire bulbar conjunctiva (the conjunctiva overlying the sclera) and the tarsal conjunctiva (the conjunctiva overlying the inside surfaces of the eyelids). Using a blue filter after instilling a drop of topical anesthetic followed by a drop of fluorescein-stained saline, it is easy to determine if there is a defect in the corneal surface epithelium. This can happen from trauma or from infections, such as pseudomonas and herpes. Motility should be evaluated also because an orbital process might cause limitation of movement and pain with movement.
Culture swabs need to be available if there is a large amount of discharge, especially if there is concern for gonorrhea or chlamydia. Cultures of the cornea need to be done at the slit lamp with special instruments. If there is a history of trauma and there is a chance the eye has been penetrated, a protective shield should be placed and the child sent to the emergency room.
History
The history is very important when trying to determine the cause of a red eye. The first question should be to ask if there has been any associated trauma. It is important to know so that you can be suspicious for a penetrating injury. Be aware, children are not always forthcoming with an accurate history if they think their actions will get them in trouble.
Next you should determine the onset and duration and whether it is unilateral or bilateral. It is helpful to know whether it started simultaneously in both eyes, or the onset of the second eye occurred after several days. This points to viral conjunctivitis.
It is important to check the vision, but you also need to ask if there have been vision changes. Sometimes the visual acuity can be normal, but there are qualitative changes, such as a visual field cut.
Next, one should explore for associated symptoms, such as photophobia, pain, itching, and swelling. It is important to ask about contact lens wear, and whether the contact is still in the eye. Knowing that the rest of the family also has conjunctivitis helps to reassure that the redness is viral, and observation is appropriate.
Red eyes can be associated with many systemic illnesses (discussed later) ( Box 1 ). That is why a complete review of systems is necessary at times to uncover the cause of the red eye. Often the child presents with various symptoms before the onset of red eyes. The red eye often helps solve the diagnostic dilemma.
History of bone marrow transplant and/or history of graft-versus-host disease
History of radiation therapy
Herpes simplex virus or varicella zoster virus infections
Juvenile idiopathic arthritis, Kawasaki syndrome, inflammatory bowel disease, systemic lupus erythematosus, Sjögren syndrome
Stevens-Johnson syndrome, toxic epidermal necrolysis
Malignancy (mucosa-associated lymphoid tissue, lymphoma, sebaceous cell carcinoma, squamous cell carcinoma)
Mucous membrane pemphigoid
Autoimmune connective tissue disease
Vitamin A deficiency
Rosacea
The red eye causes and treatments
The causes of red eye can be grouped by etiology. The major categories include infectious (viral and bacterial), inflammatory, traumatic, structural, toxic and chemical, related to external disease, and foreign body including contact lenses.
Viral Conjunctivitis
One can spot a child with viral conjunctivitis in the waiting room; after rubbing their red, glassy eyes and runny nose, they happily touch every toy, magazine, and surface possible until they can be called into the office. Symptoms of tearing, discharge without significant purulence, redness, and conjunctival chemosis (boggy swelling of the conjunctiva) predominate. Commonly, one eye is initially involved and then the other eye follows several days later through autoinoculation of the virus. History often highlights systemic upper respiratory infection symptoms, and sick contacts. Physical examination may reveal a palpable lymphadenopathy ( Box 2 , Fig. 1 ).
Treatment: Viral Conjunctivitis
Supportive care
Symptoms should decrease within the first week but may persist
Antibiotics do not hasten the resolution of a viral conjunctivitis
Cool compresses, artificial tears for comfort
No school or daycare for several days because it is highly contagious
In severe forms of infectious and/or inflammatory conjunctivitis, a low-dose topical steroid may be indicated
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Given the possible side effects, standard practice patterns recommend topical corticosteroid drops be prescribed and monitored by an ophthalmologist
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When to Refer: Viral Conjunctivitis
No resolution of symptoms within a week
If vision is affected
Severe photophobia or pain
Organized inflammatory membranes in the cul de sac of the conjunctiva
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These can lead to symblepharon (fusing of the eyelid conjunctiva to the eyeball) and require management by ophthalmology
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Pharyngoconjunctival fever
Pharyngoconjunctival fever is the most common viral conjunctivitis. It is associated with an upper respiratory tract infection and is typically caused by serotypes of adenovirus.
A much more aggressive variant of pharyngoconjunctival fever is epidemic keratoconjunctivitis, which is more contagious and dramatic clinically. Epidemic keratoconjunctivitis is associated with a hemorrhagic conjunctivitis, and may lead to subepithelial inflammatory deposits of the cornea, which may blur vision and cause photophobia and pain ( Fig. 2 ).
Herpetic eye disease
Herpes simplex virus or varicella zoster virus can cause a conjunctivitis and severe eye damage. If there are vesicular lesions near the eyelid margin, eye redness in a patient with suspected zoster or herpes simplex, or a history of previous ocular herpetic disease, an urgent referral is warranted.
Although varicella zoster tends to affect the thoracic dermatomes, the V1 distribution is a common area for the virus to reactivate. Herpetic corneal disease has a classic branching, dendritic pattern, best visualized with fluorescein staining.
Conjunctivitis associated with herpes simplex virus or varicella zoster virus should be evaluated by a pediatric ophthalmologist as soon as possible. Treatments include oral antivirals, such as acyclovir and valacyclovir, and topical antiviral and steroid medications. If the pediatrician is highly suspicious of herpetic eye disease, and immediate ophthalmology care is unavailable, starting oral acyclovir is appropriate ( Figs. 3 and 4 ).
Molluscum contagiosum
Molluscum contagiosum is caused by a poxvirus and can lead to round, raised, flesh-colored bumps of the skin, with a small indentation. When near the eye, it can cause a follicular type of conjunctivitis that may be chronic. Given that each molluscum lesion releases virus particles, it can be difficult to eradicate with topical medications. The lesions may need to be frozen or excised to achieve resolution.
Bacterial Conjunctivitis
The classic hallmark of bacterial conjunctivitis is unilateral purulent discharge. It is accompanied by redness and chemosis (swelling) of the conjunctiva. Bacterial conjunctivitis is commonly caused by normal flora of the body, such as Staphylococcus aureus , Staphylococcus epidermidis , Streptococcus pneumococcus , Streptococcus viridans , Haemophilus influenza , Escherichia coli , and Pseudomonas aeruginosa . Transmission is by direct hand-to-eye contact or from ascension from the patient’s infected nasopharyngeal mucosa.
Acute bacterial conjunctivitis is of less than 3 week’s duration. A careful history should be taken for febrile illness, other sick contacts, and concomitant genitourinary or gastrointestinal illness. As for all red eyes, vision and cornea checks are very important. Not all bacterial conjunctival infections are benign.
Neisseria- associated bacterial conjunctivitis is very purulent and has a severe onset of major symptoms in less than a day. Clinical signs of meningismus or significant febrile illness may indicate a conjunctivitis caused by bacteria, such as Neisseria meningitides ; emergent referral to a hospital may prevent morbidity and mortality from meningitis. Neisseria gonorrhea and Streptococcus pyogenes are associated with corneal ulcer and perforation. Gonorrhea conjunctivitis may be associated with conjunctival membranes.
Chlamydia trachomatis is still the worldwide leading infectious cause of blindness, and may cause chronic follicular-type conjunctivitis with permanent scarring and inflammatory changes to the eye. Children with concern for gonorrheal or chlamydial eye infections should be referred to pediatric ophthalmology immediately.
Chlamydia and gonorrhea eye infections, when not in the neonatal period, may indicate sexual abuse. The clinician must be vigilant to explore this issue and if appropriate report to Child Protective Service, law enforcement, or public health institution as required by state or federal law.
Treatment
Topical antibiotic drops or ointment is the classic and effective treatment. Well-tolerated topical eye antibiotics include polymyxin B–trimethoprim drops, or erythromycin and bacitracin ophthalmic ointment. These are appropriate broad-spectrum first-line therapies. Good hand hygiene is very important, and patients and families should be educated. Flush with saline solution to remove purulence and decrease the bacterial load as needed.
A common question is whether or not to culture discharge. If there is marked purulence or a hyperacute onset of symptoms, then conjunctival culture is warranted. Also, culture should be performed in patients who are immunocompromised. If N gonorrhea or C trachomatis are suspected, a Gram stain and culture are indicated along with prompt referral to a pediatric ophthalmologist.
If a child is too uncooperative or uncomfortable to examine in the office, they should be referred to the ophthalmologist. The ophthalmologist can cheat and insert a speculum to get a better view. Clinical reasons to refer immediately include (1) decreased vision, (2) no significant improvement in symptoms within 2 to 3 days, and (3) evidence of corneal involvement.
Neonatal Conjunctivitis
Conjunctivitis occurring within the first month of life is termed neonatal conjunctivitis. Neonatal conjunctivitis may be a chemical or infectious conjunctivitis ( Fig. 5 ).
