Herpes zoster or shingles is caused by the same virus that causes chicken pox. After the first infection, the virus may remain latent in some nerve fibers and become active again due to stress, pregnancy, compromised immune system, certain drugs or aging. Reactivated herpes zoster affects only one side of the face or body, beginning as a rash and developing into red patches which later become blisters and sores. It can also affect the eye (eg corneal infection and scarring, conjunctivitis, involvment of the retina and optic nerve).
Signs and symptoms of herpes zoster infection include fever, headache, fatigue, rash, erythematous and sensitive skin, blisters and sores, itching, tingling, burning and pain sensations. Shingles is painful as the virus travels along the nerves to get to the skin, causing damage and inflammation along the way. When the eye is affected, symptoms include redness, dryness and sensitivity to light. Other eye problems may include inflamed eyelids, blurring vision, corneal infection and scarring, glaucoma, cataract, diplopia or double vision and loss of sensation.
Herpes zoster can be diagnosed through physical examination and laboratory tests. Physical examination includes location, description and measurements of sores. Ophthalmoscopes and slit-lamp microscopes examine the eye. Visual acuity and intraocular pressure should also be monitored. Blood tests detect the presence of infection.
Treatment of herpes zoster consists of anti-virals (eg Acyclovir), ant-inflammatory drugs (eg NSAIDS) and topical creams (eg Cortisone). The blisters should not be forced to open. The sores may be washed by compressing them with vinegar (diluted with lukewarm water) for at least ten minutes twice a day. As crusts and scabs leave the skin dry, petroleum jelly may be applied to the area. The blisters and sores usually heal in two to four weeks but may leave scars. Ocular herpes zoster is managed with eye drops and / or ointments.
Discomfort may persist even after the sores have healed. Posttherpetic neuralgia refers to pain that may continue up to six months as nerves heal very slowly.