A 6-year-old boy is brought to the clinic by his parents due to 3 weeks of itchy, red eyes. The patient has had intermittent, mild, clear eye drainage and rubs his eyes frequently. These symptoms have worsened so that he now has difficulty paying attention at school. His parents have noticed some light crusting of both eyes when he wakes up in the morning. The patient has a history of mild, intermittent asthma for which he uses an albuterol inhaler. He lives with his parents, little sister, 2 cats, and a hamster. His sister has had rhinorrhea, cough, pharyngitis, and fever for 2 days. Vital signs are normal. Examination shows bilateral, diffuse conjunctival injection and mild eyelid edema. The child has no photophobia. Visual acuity is 20/20 in both eyes. Which of the following is the most likely etiology of this patient's condition?

Question

A 6-year-old boy is brought to the clinic by his parents due to 3 weeks of itchy, red eyes.  The patient has had intermittent, mild, clear eye drainage and rubs his eyes frequently.  These symptoms have worsened so that he now has difficulty paying attention at school.  His parents have noticed some light crusting of both eyes when he wakes up in the morning.  The patient has a history of mild, intermittent asthma for which he uses an albuterol inhaler.  He lives with his parents, little sister, 2 cats, and a hamster.  His sister has had rhinorrhea, cough, pharyngitis, and fever for 2 days.  Vital signs are normal.  Examination shows bilateral, diffuse conjunctival injection and mild eyelid edema.  The child has no photophobia.  Visual acuity is 20/20 in both eyes.  Which of the following is the most likely etiology of this patient's condition?

Quizplus · Accepted Answer

11ec25c8_d700_9842_bc81_5b9053b9e6b0_MD0003_00 Allergic conjunctivitis (AC) is caused by IgE-mediated acute hypersensitivity to environmental allergens. Episodes may be acute if due to a transient exposure (eg, pet dander) but more commonly are seasonal (pollen) or perennial (mold, dust). As in this patient, symptoms include bilateral ocular pruritus, conjunctival injection, and eyelid edema. Patients often have clear discharge and mild crusting, but AC does not cause purulent discharge, visual changes, or pain. The diagnosis is clinical and more common in those who have other atopic diseases (eg, asthma, allergic rhinitis), as in this patient. Treatment includes allergen avoidance when possible. AC can be treated topically with antihistamines, mast cell stabilizers, and artificial tears. Oral antihistamines can be helpful for patients with concomitant allergic rhinitis but may have systemic adverse effects (eg, sedation). (Choice A) Corneal abrasion is due to trauma to the eye surface by a foreign body. Symptoms include acute, severe eye pain and photophobia, neither of which is present in this patient. (Choice B) Bacterial conjunctivitis in children is typically caused by Streptococcus pneumoniae and Haemophilus influenzae. Patients have acute, copious, purulent discharge, unlike this child with mild, chronic tearing. (Choice D) Dacryostenosis (obstruction of the nasolacrimal duct) is most common in infancy and causes tearing and crusting. Conjunctival injection and eyelid edema are not seen. (Choices E and F) Viral conjunctivitis, most commonly due to adenovirus, causes acute conjunctival injection and watery or mucoid discharge. However, patients often have a viral prodrome (eg, fever, pharyngitis), and symptoms typically begin to improve within 5 days, making this an unlikely diagnosis in this patient with 3 weeks of symptoms. Adenovirus, as well as herpes simplex virus, can also cause keratitis (infection of the cornea), which presents with severe ocular pain, photophobia, and poor visual acuity; none of these are seen in this patient. Educational objective: Allergic conjunctivitis is an IgE-mediated hypersensitivity to environmental allergens and presents with ocular pruritus, bilateral conjunctivitis, and clear discharge. Treatment includes allergen avoidance and topical therapy (eg, antihistamines, mast cell stabilizers). References: Allergic conjunctivitis: current concepts on pathogenesis and management. (http://www.ncbi.nlm.nih.gov/pubmed/29552874) Epidemiology of allergic conjunctivitis. (http://www.ncbi.nlm.nih.gov/pubmed/21785348)

A 6-Year-Old Boy Is Brought to the Clinic by His