This is a common skin disease that causes patches on the skin. Most frequently you will see on larger patch, with many smaller patches surrounding it. Your doctor may refer to this large patch as the mother patch. The smaller patches are daughter patches. Pityriasis rosea (pit-uh-rahy-uh-sis row-zee-ah) usually disappears on its own without treatment. You can expect to see the rash for about 6 to 8 weeks. Sometimes the rash lasts much longer.
This rash can be itchy and cause other problems associated with it. It is not unusual to see this rash during pregnancy, but you should report it to your doctor. This rash usually occurs on people between the ages of 10 and 35.
No one knows what causes pityriasis rosea. Research shows that it is not an allergy. We also know that fungi (plural of fungus) and bacteria do not cause this skin disease. A virus may be the cause, but researchers have yet to prove this. It is possible that a virus causes pityriasis rosea, but this skin disease does not seem to be contagious. It does not seem to spread from one person to another.
This skin disorder mostly affects children and young adults. The exact cause of pityriasis alba is unknown. However, it’s believed that the condition may be associated with eczema, a common skin disorder that causes scaly, itchy rashes. People with pityriasis alba develop red or pink patches on their skin that are usually round or oval in shape. The patches will usually clear up with moisturizing creams or go away on their own. However, they often leave pale marks on the skin after the redness has faded. People with pityriasis alba get round, oval, or irregular patches of pale pink or red skin. The patches are usually scaly and dry. They may appear on your face, which is the most common place, upper arms, neck, chest and back
Pale pink or red spots may fade into light colored patches after several weeks. These patches usually clear up within a few months, but they can last for several years in some cases. They’re more noticeable in the summer months when the surrounding skin becomes tan. The patches won’t become tan after sun exposure. However, wearing sunscreen may make patches less noticeable in the summer months. The light patches are also more noticeable in people with darker skin.
An Eczema Link?
The exact cause of pityriasis alba isn’t known. However, it’s commonly considered a mild form of atopic dermatitis. Atopic dermatitis is a type of eczema. Eczema may be caused by an overactive immune system that aggressively responds to irritants. Normally, the immune system ignores normal proteins and only attacks the proteins of harmful substances, such as bacteria and viruses. If you have eczema, however, your immune system may not always distinguish between the two, which causes inflammation. It’s similar to having an allergic reaction. The skin’s ability to act as a barrier is reduced in people with eczema. Most people outgrow eczema and pityriasis alba by early adulthood, and it isn’t contagious but it can reoccur. It usually goes away in adulthood.