Have you been ordering lab work for suspected herpes cases? You should. Serology can help exclude herpes simplex virus (HSV) as a diagnosis for patients with chronic corneal conditions, a study in Eye & Contact Lens reports.

Keratitis caused by HSV is a frequent consideration for patients presenting with chronic, and often atypical, corneal pathology and HSV serology is a widely available, inexpensive test that may assist with the evaluation, the researchers noted.

The investigation included 54 patients with a corneal condition that lasted more than six weeks for which HSV was suspected. A single cornea specialist treated and performed serology on the patients between 2011 and 2018.

The study classified the patients as presenting with corneal ulcers (46.2%), stromal keratitis (24.1%), superficial keratitis (18.5%) or keratouveitis (11.1%). Investigators reported the prevalence of HSV-1 and HSV-2 antibodies were 42.6% and 18.5%, respectively, including five patients (9.3%) who were positive for both.

Researchers noted serology impacted the management of all patients with negative titers (48.1%); the clinician chose to discontinue antiviral medication, forego it in the first place or continue the regimen for a non-HSV etiology such as varicella zoster keratitis.

The study found no patients with HSV serology were ultimately diagnosed with HSV keratitis.

 “Although positive results have little utility, negative serology may allow a provider to narrow their differential diagnosis and avoid unnecessary initiation or continuation of antiviral therapy. The down-trending prevalence of HSV in the general population may increase the utility of this sometimes overlooked tool for the evaluation and management of chronic corneal pathology,” the researchers wrote in their paper.

The patients’ prevalence of HSV antibodies in this investigation was comparable with previous population-based studies, they added.