Herpes zoster ophthalmicus

### What you need to know A 70 year old man attended with a two day history of painful vesicular rash affecting the left forehead accompanied by a red, painful left eye. Three days before the onset of the rash, he had experienced a tingling sensation at the left forehead. A clinical diagnosis of herpes zoster ophthalmicus with ocular involvement was made. Herpes zoster, or shingles, is a common infection caused by the reactivation of varicella zoster virus that lies dormant in the dorsal root nerve ganglion following primary chickenpox infection. Herpes zoster ophthalmicus accounts for 10-20% of cases of herpes zoster infection.1 Patients usually present with painful, vesicular, dermatomal rashes affecting the ophthalmic division of the trigeminal nerve (V1). The diagnosis is usually made on clinical grounds but a viral swab can confirm the diagnosis. Herpes zoster ophthalmicus may present with ocular involvement such as conjunctivitis, keratitis, iritis, and uveitis. It can also present without ocular involvement (where only the skin of the V1 dermatomal region is affected). Herpes zoster infection may rarely present without any cutaneous manifestation, also known as “zoster sine herpete,” with or without ocular involvement, rendering the diagnosis more difficult.2 This article aims to discuss the key points to cover in a history, examination, and initial management plan for a person attending primary care with a likely diagnosis of herpes zoster ophthalmicus. ### History #### Presenting complaint When did the rash start? Starting oral antiviral treatment within 72 hours of the onset of rash substantially reduces …