There are many different types of skin rashes. Certain rashes are typically experienced during childhood, such as cradle cap and diaper rash. Some of the more common rashes for all ages include:

• Pityriasis rosea (Christmas tree rash). A fine, scaly rash that ranges in color from pink to tan. It often starts as a larger spot (herald rash) at the spine or midline of either the front or back of the body and spreads outward. The rash is characterized by mild itching, flaking and peeling. It usually resolves without treatment, but can last from four to 16 weeks. Ultraviolet light may help resolve the rash quicker. The origin of the rash is unknown, but it may be caused by a virus.
  
  
• Drug rashes. Any medication can cause an allergic reaction that manifests as a skin rash. The most common sources of drug rashes include antibiotics, anti-seizure medications and diuretics (increase urine production). An ingredient called neomycin – found in many antibiotic creams, ointments, lotions, ear drops and eye drops – may cause a rash in some people. In most patients, drug rashes begin within two weeks of beginning to take the medication. It starts as discrete red spots that spread and cover large areas of the body. Drug rashes can sometimes indicate a serious or potentially life-threatening allergy. They usually disappear within three weeks of ceasing to take a medication.
  
  
• Eczema. An itchy, noncontagious inflammation of the skin. In most cases, eczema begins as intense itching, followed by a rash that is patchy and made up of dry, flaky lesions that appears over reddened and inflamed areas. The rash most often affects the face, arms and legs as well as the creases of the hands and feet. Often used interchangeably with the term “dermatitis,” eczema appears in many different varieties, including atopic dermatitis, contact dermatitis, seborrheic dermatitis, perioral dermatitis and dyshidrotic dermatitis.
  
• Heat rash (prickly heat). Rash that often appears in hot and humid conditions and is caused by temporarily blocked active sweat glands. It usually affects the neck, the upper chest, the groin, under the breasts and the elbow creases. Miliaria rubra appears as red clusters of small blister-like bumps that cause a stinging sensation, whereas miliaria crystallina appears as clear, fluid-filled bumps that do not produce other symptoms. Heat rash usually resolves if the area is kept cool and dry.
  
  
• Hives (urticaria). A skin disorder in which itchy bumps of varying sizes appear suddenly anywhere on the body. These skin eruptions form when blood plasma leaks out of small blood vessels in the skin, usually as a result of the release of a chemical called histamine.
  
  

  

• Intertrigo. Occurs in warm, moist areas where the skin rubs or presses together, such as under the arms, in the groin area, between folds in the abdomen or under the breasts. Moisture, bacteria or fungi cause intertrigo, which is often red and painful. In severe cases, the skin may crack and bleed. Intertrigo usually resolves when patients keep the affected area dry and avoid tight, restrictive clothes.
  
  
• Lichen planus. A rash that appears as rows of itchy, flat-topped lesions. The lesions, which are red to purple in color, often appear on the arms and legs. It may also affect the scalp or mucous membranes lining the mouth, nose, vagina or anus. In most cases, the cause of this rash cannot be determined, although it sometimes stems from an allergic reaction to a medication or from chronic hepatitis (a liver disease). The rash can last for months or even years before disappearing, and may recur later. It is not contagious.
  
  
• Psoriasis. A common skin disease related to the immune system. Psoriasis is marked by raised, inflamed lesions that join together to form patches with distinct borders. The lesions are covered with flaky scales due to the rapid turnover of cells in the epidermis. It is not contagious, but is related to family history. It may be minor or serious and may cycle through remissions and flares. Psoriasis tends to affect the knees, elbows, trunk and scalp.
  
  
• Ringworm. A rash caused by a fungus that appears as itchy, red, raised and expanding rings. It tends to appear on the trunk, face, groin or thigh fold and grows outward as the infection spreads. Ringworm is contracted from pets, soil or other humans through skin-to-skin contact. It usually requires prescription medication before it clears.
  
  
• Rosacea. A chronic skin condition that leads to redness, inflammation and acne-like bumps on the nose, forehead, cheeks, chin and sometimes the eyes. Because it resembles acne, rosacea is sometimes called acne rosacea or adult acne. The cause of rosacea is unknown, but several factors have been identified that trigger flare-ups, including spicy floods, alcohol, sunlight, caffeine, menopause, certain medications (e.g., vasodilators) and stress. Rosacea is a progressive condition, which means that it gets worse over time. It can be inherited and is more common in fair-skinned people.
  
  
• Shingles (herpes zoster). A viral infection caused by the varicella-zoster virus (VZV), the same virus that causes chicken pox. After a person has had chicken pox, VZV remains in a dormant state in nerve roots for the rest of a person’s life. VZV may reactivate years later in the form of a painful rash known as shingles. It usually affects just one side of the body and resolves within two or three weeks without treatment.
  
  
• Swimmer itch. A patchy, red rash caused when the skin comes into contact with water contaminated with parasites. This causes a mild reaction in which the skin becomes red and appears as raised, itchy areas, sometimes resembling small pimples or blisters. The skin may also tingle or burn. In most cases, only skin not covered by swimsuits, wet suits or waders is affected. Swimmer itch often appears within 48 hours of exposure to the water and may last up to a week.