Shingles, also known as herpes zoster, represents the reawakening of the virus that causes chicken pox within the roots of spinal or cranial nerves. The word "shingles" derives from the Latin word "cingulum," which means belt or girdle, while "zoster" has the same meaning in Greek. These names, according to the National Institute of Neurological Disorders and Stroke, underscore the disease's development on the lower back and the trunk. Since shingles lesions develop in crops, doctors use the term "sentinel" to describe the first set of shingles skin lesions to appear.
Clinical Features
In the 2008 edition of "Fitzpatrick's Dermatology in General Medicine," National Institutes of Health dermatologist Steven E. Straus reports that the characteristic skin lesion of shingles is a 2- to 3-mm, elliptical blister that is typically oriented in parallel with skin folds and sits on a patch of red, swollen skin. All shingles skin lesions are identical. However, sentinel lesions develop first.
Time Frame
NINDS notes that new shingles lesions typically continue to appear over a period of three to five days. All lesions follow the same pattern, where the clear fluid that initially fills the blister gives way to cloudy pus. The lesions then develop a central depression or "umbilication" as the pustular fluid is resorbed by the immune system. Finally, between seven and 10 days, according to NINDS, the lesions start to crust, signaling that the disease is no longer contagious. Sentinel lesions are the first to appear and the first to heal.
Location
According to University of Alabama Professor of Infectious Diseases Richard J. Whitely in the 2008 edition of "Harrison's Principles of Internal Medicine," most shingles cases involve the skin territories supplied by nerves between the T3 through L3 levels of the spinal cord. The remainder involve the head, face and scalp. Sentinel lesions usually develop towards the midline of the body, notes Whitley, with later lesions fanning out to the periphery.
Associated Symptoms
In addition to its characteristic skin rash, shingles also produces a mild flu-like illness and pain. Both precede the onset of the skin rash by 48 to 72 hours, says Whitely. However, with the appearance of sentinel lesions, pain often changes from mild burning, tingling, soreness or sensitivity to severe, deep, stabbing, aching pain that some patients compare to being stabbed by an electric knife.
Treatment
Although shingles usually resolves with no treatment at all, NINDS recommends antiviral drugs to reduce the duration and severity of the disease, as well as the risk of complications. Patients should contact their doctors as soon as sentinel lesions appear, since antiviral drugs work better the sooner they are started. Common choices, according to the Mayo Clinic, include acyclovir, valacyclovir and famciclovir.
References
- National Institute of Neurological Disorders and Stroke: Shingles
- "Fitzpatrick's Dermatology in General Medicine, 7th Edition;" K. Wolff et al.; 2008
- "Harrison's Principles of Internal Medicine, 17th Edition;" A.S. Fauci et al.; 2008
- MayoClinic.com: Shingles
