Herpes Zoster - Prognosis

Prognosis

The rash and pain usually subside within three to five weeks, but about one in five patients develop a painful condition called postherpetic neuralgia, which is often difficult to manage. In some patients, herpes zoster can reactivate presenting as zoster sine herpete: pain radiating along the path of a single spinal nerve (a dermatomal distribution), but without an accompanying rash. This condition may involve complications that affect several levels of the nervous system and cause many cranial neuropathies, polyneuritis, myelitis, or aseptic meningitis. Other serious effects that may occur in some cases include partial facial paralysis (usually temporary), ear damage, or encephalitis. During pregnancy, first infections with VZV, causing chickenpox, may lead to infection of the fetus and complications in the newborn, but chronic infection or reactivation in shingles are not associated with fetal infection.

There is a slightly increased risk of developing cancer after a herpes zoster infection. However, the mechanism is unclear and mortality from cancer did not appear to increase as a direct result of the presence of the virus. Instead, the increased risk may result from the immune suppression that allows the reactivation of the virus.

Although herpes zoster typically resolves within 2 weeks, certain complications may arise:

• Secondary bacterial infection
• Motor involvement – including weakness especially in "motor herpes zoster"
• Eye involvement – trigeminal nerve involvement (as seen in herpes ophthalmicus) should be treated early and aggressively as it may lead to blindness. Involvement of the tip of the nose in the zoster rash is a strong predictor of herpes ophthalmicus.
• Postherpetic neuralgia – a condition of chronic pain following herpes zoster