NEW YORK (Reuters Health) – Almost 75% of cases of infectious scleritis result from herpes virus, but the diagnosis is often missed, a new paper warns.
Such infection is more common than might be generally thought, said senior author Dr. C. Stephen Foster of Harvard Medical School in email to Reuters Health.
“Recurrent episcleritis, scleritis and/or conjunctivitis,” he pointed out, “may occur as a consequence of herpes simplex virus traveling from the trigeminal ganglion to the site of inflammation, after provocation to reactivate from latency, causing recurrent inflammation in any of these tissues.”
“Diagnosis of the cause of the recurrent inflammation is typically delayed, often by years,” he added, “through failure of the practitioner to consider herpes as a possible cause, much less performing appropriate studies aimed at that possibility.”
Identifying the problem and treating it with chronic anti-viral therapy “can be life-changing through freedom from the morbidity associated with a life of recurrences,” Dr. Foster said.
In a March 28 paper online in Ophthalmology, Dr. Foster and colleagues present data on 500 patients with scleritis, gathered in a retrospective study of records at the Massachusetts Eye Research and Surgery Institution in Cambridge and the Institute Clinic of Ophthalmology Hospital Clinic in Barcelona, Spain. In 47 patients, scleritis had an underlying infectious cause, including 35 (74.4%) with herpes. The other single major cause was tuberculosis in five patients (10.6%).
Most patients with herpetic scleritis presented with acute (85.7%) and unilateral (80%) scleral inflammation. Most (68.6%) also had moderate or severe pain.
Unilaterality was more common in herpetic vs idiopathic scleritis (80% vs 56.7%) as was necrotizing anterior scleritis (8.6% vs 1.2%). Vision loss was also significantly more common (34.3% vs 11.5%).
The researchers note that the reported prevalence of herpetic scleritis varies between 4.2 to 7.5% and their 7.0% finding is in line with higher assessments.
The diagnosis, they say, may be challenging. Indicators include unilateral presentation, moderate-to-severe pain, associated uveitis or keratitis, and acute onset.
“Scleral biopsy is very helpful in diagnosing herpetic scleritis,’ the authors note. “However, when not available, response to oral acyclovir might be considered.”