Pityriasis alba is a non-cancerous, common skin condition affecting children. Pityriasis alba patches are more apparent in summer, especially in dark-skinned children, because they don't tan as well as the surrounding skin. The condition is frequently more apparent and cosmetically bothersome in patients with darker complexions. Pityriasis alba is a common rash that affects the face, neck, arms and trunk of children and young adults. This condition is not dangerous or contagious. Pityriasis alba is a mild form of dermatitis of unknown cause. It will clear up after a few months, or in some cases persist two or three years. The colour gradually returns completely to normal. Pityriasis alba appears as superficial, pale pink to light brown macules with irregular, poorly circumscribed margins. It is round-to-oval in shape and can have slightly elevated borders. Initially the lesion starts as a subtle erythema, which progresses over weeks to produce the characteristic off-white macule with powdery scale.
Pityriasis Alba depend on the body symmetric minimally scaly hypopigmented discrete and confluent macules. Rarely, the disease may be quite extensive. Patients with extensive PA present with numerous lesions on the trunk and extremities. This form of PA generally occurs in older patients, and the lesions may be more persistent. Pityriasis alba can also be confused with vitiligo. Hypopigmentation may occur in other disorders, such as those caused by fungi previous inflammatory conditions , idiopathic disorders or malignancy or it may occur secondary to medications such as retinoic acid, benzoyl peroxide, and topical steroids. Pityriasis alba can be distinguished from vitiligo by the border of the rash. The rash of vitiligo has a very distinct border with a sharp line between normal and lighter-colored skin. Although no treatment is necessary for the full skin color to return, lotions and moisturizers may help the skin return to normal faster. One percent hydrocortisone cream may also help to make the patches go away a little more quickly.
Causes of Pityriasis alba
The condition is not contagious, and no infectious agent has been identified. Pityriasis alba is a mild form of dermatitis of unknown cause. It will clear up after a few months, or in some cases persist two or three years. In the winter months when the skin is drier, the rash may be flakier. Pityriasis alba is most noticeable in the summertime when the surrounding skin gets tanner, because it remains the same color. It may resemble a fungus infection of the skin, but it is unrelated.
Common causes and risk factors of Pityriasis alba:
- Excessively dry skin.
- Heavily scented detergents or soaps.
- Abrasive clothing.
- Exposure to direct sunlight.
- A personal or family history of asthma, allergies, or atopic eczema.
Signs and Symptoms of Pityriasis alba
Pityriasis alba appears as superficial, pale pink to light brown macules with irregular, poorly circumscribed margins. It is round-to-oval in shape and can have slightly elevated borders. Initially the lesion starts as a subtle erythema, which progresses over weeks to produce the characteristic off-white macule with powdery scale. Patients are usually asymptomatic but can experience mild pruritus or burning. The patches are dry with very fine scales. They most commonly occur on the face, but in 20% appear also on the upper arms, neck, or shoulders.
Sign and symptoms may include the following :
- Skin lesions spreads very fast in chronic condition.
- May redden quickly in the sun.
- Smooth flat pale patches.
- Skin redness or inflammation may occur.
Treatment for Pityriasis alba
Treatment of the rash is not necessary since it will resolve on its own. One percent hydrocortisone cream may also help to make the patches go away a little more quickly. One percent hydrocortisone cream available over the counter should be applied once to twice a day to the affected areas. Ultraviolet B in erythema exposures should be used to expedite the involution of lesions after the acute inflammatory stage has passed. Etretinate has also been reported to be effective. Vitamin A with the possible addition of vitamin E is often effective.
Treatment may include:
- No treatment is necessary, but a moisturizing cream may improve the dry appearance.
- If the patches are red or itchy, a mild topical steroid cream can be applied for a few days. Pimecrolimus cream has also been reported to be effective.
- Antihistamines by mouth are also beneficial.
- Although no treatment is necessary for the full skin color to return, lotions may help the skin return to normal faster
- The cool baths with or without oatmeal helps in the removal of patches.
- Oral medications helps to soothe the itching.