Our skin is filled with special cells of the immune system. These cells protect the skin and body against viruses, bacteria, and other threats. Whenever these cells detect a suspicious substance, they begin a chain reaction in the skin that leads to inflammation. The medical name for this reaction is dermatitis. But it’s more commonly known as a rash.
There are many different types of dermatitis and each has a distinct set of causes, symptoms, and treatments.
Atopic dermatitis, often called eczema, is a long-lasting disease that causes the skin to become inflamed and irritated. Atopic dermatitis is a common condition, and anyone can get the disease. It usually begins in childhood and goes away before the teenage years. However, it can last into adulthood or start later in life.
No one knows what causes atopic dermatitis; however, doctors know that changes to the skin can cause it to dry out. This can lead to damage and cause the skin to become inflamed.
The most common symptom is itching, which can be severe. Other symptoms include:
Treatments usually include a combination of therapies such as medications, moisturizers, and phototherapy. Goals include:
A skin allergy, or allergic contact dermatitis, produces a red, itchy rash that sometimes comes with small blisters or bumps.
Allergic dermatitis is caused by a substance you’re exposed to that irritates your skin or triggers an allergic reaction. It is important to note that your immune system might not react the first time you encounter an allergen. But over time, your immune system can become sensitive to the substance. As a result, your next contact may lead to inflammation and an allergic rash. Allergens can come from certain jewelry, soaps, creams and even pets. Other common causes of allergic dermatitis are poison oak and poison ivy.
Certain drugs, including antibiotics like amoxicillin, may also cause itchy skin rashes. If you’re allergic to a drug, a rash can be the first sign of a serious reaction. NOTE: not all drug rashes are due to an allergy. If you break out in itchy spots after starting a new prescription, contact your doctor right away.
Mild cases of allergic contact dermatitis usually disappear after a few days or weeks. But if the rash persists, is extremely uncomfortable, or occurs on the face, it’s important to see a physician. A doctor can prescribe medications that will tone down the immune reaction in the skin. This eases swelling and itching.
While most rashes get better with time, some can last a lifetime. Psoriasis is a common, long-term (chronic) disease with no cure. There are several types of psoriasis. Most types of psoriasis go through cycles, flaring for a few weeks or months, then subsiding for a time.
Psoriasis is thought to be an immune system problem that causes the skin to regenerate at faster than normal rates. Just what causes the immune system to malfunction isn’t entirely clear. Researchers believe both genetics and environmental factors play a role.
Psoriasis symptoms can vary from person to person and can include:
While there’s no cure for psoriasis, treatment can stop skin cells from growing so quickly, which reduces inflammation and the formation of plaques. Treatment plans are based on the severity of the psoriasis and its location on the body.
Because rashes can be caused by many different things, it’s important to figure out what kind of dermatitis you have. If you have any significant rash, you should see a dermatologist.
Sources: newsinhealth.nih.gov, mayoclinic.org