Shingles, the medical name of which is herpes zoster, probably is an infectious disease. Just as its cousin, herpes labialis, or fever blisters, is closely related to infection. What the nature of the infection is, is not determined as yet, but it is generally considered among bacteriologists as one of the diseases due to a filterable virus.
The infection has an affinity for the ganglia of the nerves of sensation. After an attack these ganglia are found to be partially destroyed by inflammation and hemorrhage. The disease usually affects only one or two ganglia, and usually only on one side of the body.
The result of this inflammation of the sensory nerves, which carry impulses of feeling and pain, naturally is the production of an extremely painful area of the skin, the area being limited to the skin supplied by the sensory nerves involved. There is no description which can do justice to the severity of this pain in the early stages of the disease. The eruption does not occur for 12 to 24 hours after the pain begins, so all the victim knows at first is the pain. One man I knew told me that for a day and a night he had a headache which he thought must have been intended for a horse.
When the eruption occurs it consists of blisters on the skin with a red inflammatory area around them.
Why the disease was called shingles is not very evident, although the appearance of the skin does suggest those lines of debris on the seashore which are so called.
People who have had an attack of shingles can afford to lose all interest in it, because one attack usually confers immunity so that it seldom occurs twice in the same person. In this it differs from herpes labialis, to which certain individuals have a predisposition to recurrent attacks. Predisposing factors in the production of shingles are exposure to cold, overwork and absorption of arsenic.
The treatment of shingles consists solely in the relief of pain in the acute stage and the protection of blisters from infection. It disappears spontaneously in about two weeks to a month.