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Pityriasis alba
Pityriasis alba is a common skin disorder of patches of light-colored (hypopigmented) areas.
Causes
The cause is unknown but may be linked to eczema and a history of allergies. The disorder is most common in children and teens. It is more noticeable in children with dark skin.
Symptoms
The problem areas on the skin (lesions) start as slightly red and scaly patches that are round or oval. They usually appear on the face, upper arms, neck, and upper middle of the body. After these lesions go away, the patches turn light-colored (hypopigmented).
The patches do not tan, but may get red quickly in the sun.
Exams and Tests
The health care provider can usually diagnose the condition by looking at the skin. Tests, such as potassium hydroxide (KOH), may be done to rule out other skin problems. In very rare cases, a skin biopsy is done.
Skin biopsy
A skin lesion biopsy is when a small amount of skin is removed so it can be examined. The skin is tested to look for skin conditions or diseases. A...
Treatment
The provider may recommend the following treatments:
- Moisturizer to help with the scales
- Mild steroid creams
- Medicine called immunomodulator applied to the skin to reduce inflammation
- Laser treatment
The patches may clear up, but often return.
Outlook (Prognosis)
Pityriasis alba usually goes away on its own with patches returning to normal pigment over time.
Possible Complications
Patches may get sunburned when exposed to sunlight. Applying sunscreen and using other sun protection can help prevent sunburn.
When to Contact a Medical Professional
Call your health care provider if your child has patches of hypopigmented skin.
References
Habif TP. Light-related diseases and disorders of pigmentation. In: Habif TP, ed. Clinical Dermatology: A Color Guide to Diagnosis and Therapy . 6th ed. Philadelphia, PA: Elsevier Mosby; 2016:chap 19.
Patterson JW. Disorders of pigmentation. In: Patterson JW, ed. Weedon's Skin Pathology . 4th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2015:chap 10.
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Skin layers - illustration
The skin is the largest organ of the body. The skin and its derivatives (hair, nails, sweat and oil glands) make up the integumentary system. One of the main functions of the skin is protection. It protects the body from external factors such as bacteria, chemicals, and temperature. The skin contains secretions that can kill bacteria and the pigment melanin provides a chemical pigment defense against ultraviolet light that can damage skin cells. Another important function of the skin is body temperature regulation. When the skin is exposed to a cold temperature, the blood vessels in the dermis constrict. This allows the blood which is warm, to bypass the skin. The skin then becomes the temperature of the cold it is exposed to. Body heat is conserved since the blood vessels are not diverting heat to the skin anymore. Among its many functions the skin is an incredible organ always protecting the body from external agents.
Skin layers
illustration
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Skin layers - illustration
The skin is the largest organ of the body. The skin and its derivatives (hair, nails, sweat and oil glands) make up the integumentary system. One of the main functions of the skin is protection. It protects the body from external factors such as bacteria, chemicals, and temperature. The skin contains secretions that can kill bacteria and the pigment melanin provides a chemical pigment defense against ultraviolet light that can damage skin cells. Another important function of the skin is body temperature regulation. When the skin is exposed to a cold temperature, the blood vessels in the dermis constrict. This allows the blood which is warm, to bypass the skin. The skin then becomes the temperature of the cold it is exposed to. Body heat is conserved since the blood vessels are not diverting heat to the skin anymore. Among its many functions the skin is an incredible organ always protecting the body from external agents.
Skin layers
illustration
Review Date: 4/14/2015
Reviewed By: Kevin Berman, MD, PhD, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
