The word "rash" covers all sorts of temporary eruptions on the skin, the body's most visible and largest organ. The causes of skin rashes include fungi, viruses, parasites, drugs and heat. Pain, itchiness and discomfort may accompany some skin rashes. Some common skin rashes resolve over time without treatment, but others require medical attention. Different common skin rashes appear on different parts of the body, and they may have distinctive features that help identify them.
Contact Dermatitis
Contact dermatitis is a common skin condition that, as its name implies, is caused by contact with substances that provoke inflammation of the skin. Symptoms include itchiness, redness and sometimes blistering. Doctors draw a distinction between two types of contact dermatitis, depending on the underlying cause. Irritant contact dermatitis is responsible for 80 percent of all contact dermatitis cases, according to the Merck Manuals Online Medical Library. Irritants include soaps, detergents, chemicals and plants such as peppers and poinsettias. Treatment options include removal or avoidance of the irritant, application of topical corticosteroid drugs, and use of antipruritic medications to treat the itchiness symptoms.
Allergic contact dermatitis involves an immune system response to an allergen. Allergens may include airborne particles, such as insecticide sprays or pollen from the ragweed plant, or substances such as chemicals, perfumes, cosmetics, soaps, poison ivy, mango peels and cashew nut shells. The same range of treatment options exist as with irritant contact dermatitis--topical corticosteroid drugs, removal or avoidance of the allergen and medication to treat the itchiness.
Swimmer's Itch
Swimmer's itch is a reaction to parasites that can exist in contaminated water. It affects exposed areas of skin not covered by a bathing suit or wet suit. The parasites enter the outer layers of the skin, where they quickly die. Their presence provokes swimmer's itch, a mild condition involving redness and itchiness. The affected areas may become raised. The condition usually disappears on its own with no treatment, but if re-exposure to the parasites occurs, subsequent episodes of swimmer's itch may involve blisters and could take longer to resolve.
Heat Rash
The common skin rash known as heat rash occurs when excessive production of sweat causes the skin to become irritated. One type of heat rash, known as milaria rubra or milaria A, features reddish groups of bumps or blisters that might sting, according to the Mayo Clinic. Milaria crystalline, or malaria B, features bumps filled with clear fluid. Heat rash appears most often in the groin or the creases of the elbow, under the breasts, and on the chest and neck, notes the National Institute for Occupational Safety and Health. Treatment involves keeping the skin dry and avoiding heat and humidity.
Drug Rash
The term drug rash refers to allergic reactions to medications. Diuretic drugs, antibiotics and anti-seizure drugs are the most common instigators of drug rash, but all medications can provoke that reaction. The Mayo Clinic says that symptoms frequently begin to appear during the first week after the beginning of treatment with a new drug. What begins as separate red spots may develop and spread to cover large areas of the skin. The rash may signal a serious reaction to the new drug, and the reaction could become life-threatening. Any occurrence of a drug rash requires immediate medical attention. Drug rash most often disappears within three weeks of cessation of treatment with that particular medication.
