The cause of a rash may be determined from its visible characteristics and other co-existing symptoms. However, the cause of many rashes is never determined.
Common causes include:
- Contact dermatitis following exposure to:
-
- Dyes and other chemicals found in clothing
- Chemicals found in elastic and rubber products
- Cosmetics
- Feminine deodorants
- Poison ivy and poison oak
- Eczema
- Medications or insect bites that cause allergic reactions
- Various diseases cause rashes, including:
-
- Measles
- Lupus erythematosus
- Roseola
- Hand-foot-mouth disease
- Fifth disease
- Juvenile arthritis
- Kawasaki disease
Most common rashes will improve with gentle skin care and avoidance of irritating substances. Avoid scrubbing the skin, minimize the use of soap (using gentle cleansers when possible), and moisturize frequently. Eliminate any newly added cosmetics or lotions. Hydrocortisone cream (1%) is available without prescription and may soothe many rashes.
Call your health care provider if home treatment is ineffective, or if symptoms persist or worsen and if other symptoms accompany the rash.
A dermatologist is most qualified to deal with skin disorders, though many primary care doctors are comfortable dealing with common rashes.
Risk factors for Rashes
Ulcerative Colitis
Skin rashes may occur as a result of the presence of ulcerative colitis and disappear when the colitis is treated.
Rashes suggests the following may be present
Recommendations for Rashes
Key
 | Weak or unproven link |
 | Strong or generally accepted link |
 | May do some good |
Glossary
Dermatitis
A general term used to refer to eruptions or rashes on the skin.
Eczema
Swelling of the outer skin of unknown cause. In the early stage it may be itchy, red, have small blisters, and be swollen, and weeping. Later it becomes crusted, scaly, and thickened.
Arthritis
Inflammation of a joint, usually accompanied by pain, swelling, and stiffness, and resulting from infection, trauma, degenerative changes, metabolic disturbances, or other causes. It occurs in various forms, such as bacterial arthritis, osteoarthritis, or rheumatoid arthritis. Osteoarthritis, the most common form, is characterized by a gradual loss of cartilage and often an overgrowth of bone at the joints.
Ulcerative Colitis
(Colitis ulcerosa): Ulceration of the colon and rectum, usually long-term and characterized by rectal bleeding or blood in the stool, frequent urgent diarrhea/bowel movements each day, abdominal pain.
Colitis
Inflammation of the colon.
