Zoster, herpes zoster, shingles
What is it?
Herpes zoster is a viral disease caused by Varicella-zoster virus, the same virus that causes varicella (chickenpox).
After chickenpox, some people do not develop full immunity to the virus, which remains latent in a ganglion near the spine. When the virus finds appropriate conditions, it undergoes reactivation, develops and reaches the skin through the nerves which correspond to that ganglion.
It affects men and women, being more common in adults and the elderly. The appearance of herpes zoster may be indicative of a low immunity, specially in young people.
Characteristics and symptoms
Herpes zoster is a self-limited disease, having a life cycle of around 15 days. Before the appearance of skin lesions, painful symptoms or paresthesias (tingling, sensitive skin or burning) appear in the affected area, due to nerve inflammation.
Pain may be very intense, often becoming unbearable, especially when it affects older people. Usualy, the pain gradually diminishes, but in the elderly, it may remain for months or years after the end of the cutaneous manifestations, featuring the post-herpetic neuralgia.
Cutaneous manifestations begin by vesicles that can merge, forming blisters containing transparent or slightly yellowish liquid, following the path of a nerve. The nerves most often affected are the intercostal (between ribs), provoking lesions in the trunk (photo below), but other nerves may be affected.
When involving the cranial nerves (photo below), symptoms related to them, as corneal ulcers, vertigo or deafness may occur.
In some days, lesions get dry, forming crusts which will be gradually released, leaving discrete spots at the site, which tend to disappear. Symptoms are limited to one side of the body, corresponding to the area innervated by the affected nerve. Bilateral involvement is rare.
Treatment should be started as soon as symptoms begin in order to avoid irreparable damage to the nerve affected, which may result in post-herpetic neuralgia. Skin lesions have spontaneous healing but measures to prevent secondary infection should be taken.
Antiviral drugs are used to treat herpes zoster and should be indicated by a dermatologist, according to each case. In some patients, systemic corticosteroids may be needed to control nerve inflammation and prevent its damage.
- Labial herpes
- Genital herpes