Herpes Zoster

Synonym: Shingles

Varicella-zoster virus (VZV) is the causative organism an the site of its pathology is the posterior root ganglion; the skin is only secondarily affected. One or several posterior root ganglia may be involved. The inflammation, sometimes, though rarely, spreads to the posterior horn and then to the anterior horn and even the meninges. Physical injuries, mental trauma, febrile illnesses and drugs are also known to act as triggers as well as predisposing factors.

Shingles may occur at any age, though of course, adults are more often affected. Occasionally, herpes zoster may take an epidemic form.

Symptoms of Herpes Zoster

An attack starts with neuralgic pain, local increased sensitivity of the skin (hyperesthesia) and fever with a range of 102° to 103° F. Cutaneous lesions develop three days after the onset of the attack. Sometimes, the rash may develop suddenly without any premonitory symptom.

The rash develops in the segmental distribution of the affected nerve roots, and consists of typical herpetic lesions e.g., groups of vesicles on inflammatory/base in several patches with intervening areas of normal skin. The contents of the vesicles soon turn opaque. The vesicles may become confluent to form flat bullae.

Prognosis of Herpes Zoster

It is good as far as the cutaneous lesions are concerned. An individual attack subsides nicely, leaving faint scars. The troublesome sequelae may be the annoying post-herpetic neuralgia and muscular paralysis due to extension of inflammation to anterior horn of the spinal cord. Viremia and meningo-encephalitis may rarely occur in susceptible patients or in patients under immuno-suppressive drugs.

Diagnosis of Herpes Zoster

It is based upon the sudden onset of a unilateral, herpetic eruption along the distribution of one or more nerve roots accompanied by pain and hyperaesthesia. In the initial stage of sudden pain, before the rash develops, confusion may occur with other local causes of pain like mastoiditis, pleurisy, appendicitis, cholecystitis, pyelitis etc.