Datingxd ru


31-Mar-2015 16:34

Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language | Individual differences | Personality | Philosophy | Social | Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology | Biological: Behavioural genetics · Evolutionary psychology · Neuroanatomy · Neurochemistry · Neuroendocrinology · Neuroscience · Psychoneuroimmunology · Physiological Psychology · Psychopharmacology (Index, Outline) Herpes zoster (or simply zoster), commonly known as shingles and also known as zona, is a viral disease characterized by a painful skin rash with blisters in a limited area on one side of the body, often in a stripe.The initial infection with varicella zoster virus (VZV) causes the acute (short-lived) illness chickenpox which generally occurs in children and young people.Once an episode of chickenpox has resolved, the virus is not eliminated from the body but can go on to cause shingles—an illness with very different symptoms—often many years after the initial infection.Herpes zoster is not the same disease as herpes simplex despite the name similarity (both the varicella zoster virus and herpes simplex virus belong to the same viral subfamily Alphaherpesvirinae).The pain and rash most commonly occurs on the torso, but can appear on the face, eyes or other parts of the body.At first the rash appears similar to the first appearance of hives; however, unlike hives, herpes zoster causes skin changes limited to a dermatome, normally resulting in a stripe or belt-like pattern that is limited to one side of the body and does not cross the midline.Later the rash becomes vesicular, forming small blisters filled with a serous exudate, as the fever and general malaise continue.

Although the rash usually heals within two to four weeks, some sufferers experience residual nerve pain for months or years, a condition called postherpetic neuralgia.

Exactly how the virus remains latent in the body, and subsequently re-activates is not understood.

Throughout the world the incidence rate of herpes zoster every year ranges from 1.2 to 3.4 cases per 1,000 healthy individuals, increasing to 3.9–11.8 per year per 1,000 individuals among those older than 65 years.

Over a lifetime, a large fraction of people develop herpes zoster, though usually only once – in a 1960s US study, 50% of individuals living to age 85 had at least one attack, while 1% had at least two attacks.

The pain may be mild to extreme in the affected dermatome, with sensations that are often described as stinging, tingling, aching, numbing or throbbing, and can be interspersed with quick stabs of agonizing pain.

In most cases after 1–2 days, but sometimes as long as 3 weeks, the initial phase is followed by the appearance of the characteristic skin rash.