SAN DIEGO—Emergency physicians seeing patients with acute red eyes need to ask one question, according to an expert at ACEP18.

Are you in pain?

That’s because pain, particularly complaints of more than mild pain, is a major marker that the cause of the acute red eye is serious enough to warrant more detailed or immediate treatment, said Megan Boysen Osborn, MD, FACEP, who presented Tuesday’s session, “Discharge or Disaster? Differentiating Between Harmless and Dangerous Causes of the Acute Red Eye.”

“You need to ask every patient with acute red eye whether or not they have pain,” said Dr. Osborn, vice chair of education and residency program director for emergency medicine at the University of California Irvine Health in Orange. “We have to know the difference between dangerous causes of acute red eye and less dangerous [causes], so that we can use resources wisely and we avoid discharging patients with sight-threatening diagnoses.”

Leading with a question about pain, Dr. Osborn has a checklist she uses to determine how seriousness of a patient’s condition. Her questions are:

• Does the patient have pain in his or her eye, and is that pain more than mild?
• Is there fluorescein uptake on the fluorescein exam?
• Do they have cells and flare in the anterior chamber?
• Do they have elevated intraocular pressure?
• Is there any decreased visual acuity?

For patients who say they are experiencing pain, emergency physicians should be on the lookout for six potential diagnoses that can be indicative of a more serious problem requiring immediate referral or potential transfer to a more appropriate facility: anterior uveitis, acute angle-closure crisis, bacterial or viral keratitis, endophthalmitis, and scleritis. One exception to the pain rule is that patients presenting with corneal abrasions will likely say they are experiencing pain.

For patients not in pain, diagnoses that should be typically considered include conjunctivitis, episcleritis, and subconjunctival hemorrhage. Those patients likely are safe to be discharged for ophthalmologic follow-up outside the emergency department.

One thing Dr. Osborn cautions emergency physicians to keep in mind is that anterior uveitis can be a manifestation of ocular syphilis, so following up with a skin exam in those patients can be helpful. While ocular syphilis is not particularly common, it is becoming a more frequent diagnosis.

“It’s on the rise,” Dr. Osborn said. “It’s something we need to be very aware of.”