The cause is unknown but is associated with eczema and a history of allergies. The disorder is most common in children and adolescents, and is more noticable in children with dark skin.
Round or oval patches of hypopigmented (lighter) skin appear on the face, upper arms, neck, and upper middle of the body. There may be flaky skin, called scales .
The patches do not tan, but may get red quickly in the sun.
Exams and tests:
The doctor 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.
Symptoms are treated with moisturizers and mild topical steroid creams. The patches usually clear up, but may return.
Pytiarisis alba usually goes away on its own with patches returning to normal pigment over time.
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: Reider N, Fritsch PO. Other eczematous eruptions. In: Bolognia JL, Jorizzo JL, Schaffer JV, eds. Dermatology. 3rd ed. Philadelphia, Pa: Elsevier Saunders; 2012:chap 13.