A rash (dermatitis) is any irritation or inflammation of the skin. Rashes can be caused by illness, allergy, or heat, and sometimes by emotional stress. For rashes related to childhood illnesses, See Childhood Rashes. If the rash developed after you were bitten by a tick, See Tick Bites.

Poison ivy and other plant rashes are often red, blistered, and itchy and appear in lines where the leaves brushed against the skin.

When you first get a rash, ask yourself these questions to help determine the cause (also See Skin Problems See Childhood Rashes):

• Did a rash that is contained to a specific area (localized) develop after you came in contact with anything new that could have irritated your skin: poison ivy, oak, or sumac; soaps, detergents, shampoos, perfumes, cosmetics, or lotions; jewelry or fabrics; new tools, appliances, latex gloves, or other objects? The location of the rash is often a clue to the cause.

• Have you eaten anything new that you may be allergic to?

• Are you taking any new medications, either prescription or nonprescription?

• Have you been unusually stressed or upset recently?

• Is there joint pain or fever with the rash?

• Is the rash spreading?

• Does the rash itch?

  The oil on the leaves of these plants can cause an uncomfortable, itchy, red skin rash with blisters or hives.