A rash is a condition of irritation or inflammation of the skin. Rashes have many forms with some being flat or scaly, and others being red, raised or blistery. They might be confined to a small area of the skin or spread over most of the body. A skin rash may result from either viral, fungal or bacterial infections. Allergies or other reactions of the immune system can also produce a rash.
Shingles
Shingles, also known as herpes zoster, is a rash caused by the chicken pox virus, varicella-zoster. Anyone who has had chicken pox is vulnerable to developing shingles at some point because the virus can become reactivated. Shingles produces painful, itchy fluid-filled blisters that form crusts. The rash only occurs on one side of the body, often on the back near the waistline, according to the National Institute of Neurological Diseases and Stroke. Pain in the affected area can be present even before the rash appears. Some may feel unwell several days before they get a rash, experiencing fever and gastrointestinal symptoms. The shingles rash often goes away in two to three weeks, but the pain may take up to two months to resolve. Sometimes the pain can last much longer and is called post herpetic neuralgia.
Cellulitis
Cellulitis is an inflammation in the skin caused by a bacterial infection. Many kinds of bacteria can cause the infection, but streptococci and staphylococci are most commonly involved, the Merck Manuals Medical Library reports. When a person gets cellulitis, it often occurs on the legs, causing an area of hot, red swollen skin that might have fluid-filled blisters. The infection can stay localized or may spread through the blood or lymph nodes. This results in a more-serious condition.
Scabies
Scabies is caused by an invasion into the upper layers of the skin by a parasite called Sarcoptes scabiei, also called the itch mite. The mite burrows through the skin, causing an intensely itchy rash that looks like an area of tiny pimples or blisters. The hallmark of scabies is escalating, relentless itching that is worse at night. After a person becomes infected with scabies for the first time it can take two to six weeks for the rash to appear, the Centers for Disease Control and Prevention reports. The rash can be anywhere on the body, but commonly affects the webs of the fingers, the wrists, elbows, waist and buttocks.
