Common Skin Rashes
What Causes Lichen Planus?
In most cases, the cause of lichen planus is not known. However, lichen planus is linked to hepatitis C infection in some cases.
Medications to treat high blood pressure, heart disease, and arthritis can cause lichen planus-type rashes that are allergic reactions to those drugs. Lichen planus is not contagious.
What Are the Symptoms of Lichen Planus?
Signs and symptoms of the condition include shiny, flat-topped bumps that are purple or a reddish-purplish color. When it appears on the scalp, lichen planus may cause hair loss. Lichen planus of the nails can cause brittle or split nails.
How Is Lichen Planus Diagnosed?
A doctor can diagnose lichen planus by its distinctive appearance or with the use of a skin biopsy. In a skin biopsy, a small bit of skin is taken from the affected area and is sent to a lab for testing.
How Is Lichen Planus Treated?
Although lichen planus cannot be cured, its symptoms can be treated with anti-itch products such as antihistamines (for example, Benadryl, or diphenhydramine). If lichen planus affects only a small part of the body, medicated cream can be applied to the affected area. Drugs such as steroid injections, prednisone, other drugs to suppress the immune system, or retinoids may be prescribed in more severe cases.
Another treatment for lichen planus is light therapy. Talk to your doctor about which treatment is right for you.
Pityriasis Rosea and Your Skin
Pityriasis rosea is a common skin rash that usually is mild. The condition often begins with a large, scaly, pink patch of skin on the chest or back. The patch usually is followed by additional pink patches of skin. There is itching and redness or inflammation of the skin. The number and sizes of the spots can vary.
What Causes Pityriasis Rosea?
The cause of pityriasis rosea is not known. However, there is evidence that suggests pityriasis rosea may be caused by a virus because the rash resembles certain viral illnesses. The rash does not seem to spread from person to person.
What Are the Symptoms of Pityriasis Rosea?
The primary symptom of pityriasis rosea is large, scaly, pink area of skin that is followed by additional skin lesions. The spots become itchy and there may be redness or inflammation of the skin. Pityriasis rosea affects the back, neck, chest, abdomen, upper arms, and legs, but the rash may differ from person to person.
How Is Pityriasis Rosea Diagnosed?
A doctor can usually diagnose pityriasis rosea by looking at it. He or she may order blood tests, scrape the skin, or do a skin biopsy to rule out other skin conditions.
How Is Pityriasis Rosea Treated?
Treatment may not be necessary in mild cases of pityriasis rosea, and even more severe cases can go away without treatment. Oral antihistamines (for example Benadryl, or diphenhydramine) can help soothe itching.
Sores may heal faster with some exposure to sunlight or ultraviolet light. Too much sun exposure should be avoided, however. In most cases, pityriasis rosea goes away within six to 12 weeks.