Human Physiology

Herpes Varicella-Zoster Virus

Jordan Rooks

OSU-OKC

Spring 2012 Human Physiology Lecture

Dr. Azartash

April 25, 2012

The disease called shingles has been recognized since ancient times. Its most obvious symptoms are a blistered rash along with itching or burning pain. Also well-known are several other basic facts, such as, it mainly attacks older people, and the older they are the more severe the attack. It almost always affects just one side of the body, and it is limited to a specific area on that side. The most common of these areas is the middle of the trunk, and the second most common is the upper face. Finally, and perhaps most importantly, the pain of shingles varies widely, but it can be agonizingly intense. Moreover, the pain may persist long after the rash has disappeared, a condition known as post-herpetic neuralgia. The name shingles is somewhat misleading. The word is singular, not plural, and it has nothing to do with building materials. It is derived from the Latin word cingulum, which means “belt,” and refers to the typical location of the rash, in a horizontal band around part of the chest or abdomen. Another word for shingles is zoster, a Greek word which also means “belt.”

Until the nineteenth century, shingles was considered a very mysterious disease. Fundamental discoveries about the nervous system, and the sensory nerves in particular, helped answer questions. It was discovered that the nerves that register sensations in the skin are laid out in symmetrical pairs, running from the base of the spine to the base of the skull. Each nerve of the pair extends from the skin to one side of the spinal column, where it connects with the nerves of the central nervous system, carrying sensations to the brain. Each nerve registers sensations from only a single body segment, called a dermatome, and individual branches of the nerve may register sensations from only a part of the dermatome. That is why the area of shingles is limited, it almost...