A rash is a change in the skin which affects its appearance or texture. A rash may be localized to one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, dry, cracked or blistered, swell and may be painful. A rash can develop on a small area of the body, or cover the entire body. Some rashes will go away after a few hours; others resolve in a few days. Diagnosis must take into account such things as the appearance of the rash, other symptoms, what the patient may have been exposed to, occupation, and occurrence in family members.
The presence of a rash may aid diagnosis of the patient's condition. Not only the appearance and sensation of the rash but also the distribution (which parts of the body are affected and where it arose and spread to) and evolution of the rash may be important, as certain patterns of rashes and their associated signs and symptoms are diagnostic of certain diseases. For example, the rash in measles is an erythematous, maculopapular rash that begins a few days after the fever starts; it classically starts at the head and spreads downwards.
Rashes could be caused by any number of things and are often the sign or only visible symptom of some other underlying condition. Common causes of rashes include:
- skin contact with an irritant
- allergies, e.g. to foods, dyes, medicines, insect stings; such rashes are often called hives. Some people are also sensitive to metals such as zinc or nickel
- plants such as poison ivy, poison oak or stinging nettle
- infection, e.g., by the viruses that cause chickenpox, smallpox, and measles
- reaction to a vaccination
- autoimmune disorders such as psoriasis
- exposure to sun (sunburn) or heat
- irritation such as clothing or denim rubbing on the skin
- lead poisoning
It is best to try and deal with a rash as soon as it develops. Some rashes are a constant source of irritation and itching. Dust, pollen, animal hair, chemicals, cleaning products, prescription and nonprescription drugs can all cause rashes. Depending on what kind of rash you have, treatment for it may be just waiting it out and relaxing (note that stress is a major cause of rashes) or getting over the counter or prescription drugs like antihistamines or anti-anxiety drugs to treat it.
If possible, get a cream or lotion that stops the itching. Wash your hands with gentle soap and water, dry them well on a clean, preferably throw-away towel, and don't touch your eyes. This is a very important point to remember. Many of the creams or lotions that are prescribed for rashes can hurt your eyes. Don't scratch! That makes things worse. You don't want to accidentally infect your eyes or spread the rash. Taking warm, instead of hot showers and wearing comfortable, soft clothing may help with itching, as well as rash resolution. Rough toweling off after a warm shower or bath is not recommended. In certain cases, you may have to apply heat to an area to break up fibrous tissue from an insect bite, for example. You may have to take antibiotics as well.
If a rash persists for more than a few days and you cannot seem to find the cause, see your physician for a full diagnosis. Treatment may then involve curing the underlying cause of the rash, as well as the rash itself (which is likely to disappear once the underlying cause is dealt with appropriately).
more informationThe Family Doctor (Skin Rashes)
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