Pityriasis alba is a chronic childhood disease. It is a skin issue that can affect kids aged between 6 and 12, with some patches of skin becoming lighter than normal. These are usually located on the face but they can also appear on the upper chest, neck or arms. The patches don't have well-defined borders and blend with the normal areas of skin.
Even if pityriasis alba typically affects children, this is not a rule. It can start at any age and affect people of all genders and races, being a lot more visible on the ones with darker skin. Despite the unpleasant aspect, the rash is not painful or dangerous. It heals by itself in time, with the patches slowly returning to the natural skin color.
Sometimes, zones with discoloured scales remain in the area of a patch that is healing. This can be alarming and some people only go to the hospital at this point, due to the threatening aspect of these scales.
The areas affected by this condition can be the same color as the skin but also red or pink, with a spherical, oval or irregular shape. They are most common on the face or the upper arms and more than one can be active at the same time. The lesions can return in the same location and the healing time varies from a few months to more than a year. They are a lot more visible on darker skin tones, as well as during the summer when the skin tans. Normally, the condition starts in childhood and heals by itself long before adult age. It is not a serious disease and the skin recovers its original color, without permanent discoloration.
The mechanism of pityriasis alba is not understood yet but scientists suspect it is a less severe type of an eczema named atopic dermatitis. The real cause might be a strong response of the immune system to some irritants. People who suffer from eczema actually have a weak skin, which is unable to stop some pathogens from entering. As a result, the immune system is unable to distinguish between the proteins of viruses and bacteria and the ones of its own tissues. In this case, it starts attacking both, causing serious damage to normal healthy cells. The visible result is usually a strong inflammation, resembling an allergic reaction. However, both normal eczema and pityriasis alba are usually gone by the time a child reaches adult age.
Besides the discoloured patches, pityriasis alba rarely has other symptoms, except minor itching in the area. The patches are round or oval and can have a scaly surface, with a mild pink color. After the rash is gone, the area remains discoloured when compared to the normal skin around it. The rash affects upper areas of the body, such as the face, upper arms or neck. The skin always returns to its normal color but the healing process can take some time.
Pityriasis alba can start at any age but it is the most common in children and teenagers. It usually affects kids aged 6 to 12 years old, an estimated 2 to 5% of them suffer from this disease. Those who suffer from the skin inflammatory condition named atopic dermatitis have a much higher risk to develop pityriasis alba as well.
Doctors have noticed some factors that seem to increase the risk even further. The disease is frequent among kids who spend a lot of time in the sun without sunscreen, as well as those who like hot baths. However, pityriasis alba is not contagious and can't be transmitted to others.
Pityriasis alba doesn't require treatment in most cases. The skin eventually restores its normal color but the process can take several months. No treatment for the condition has been discovered. In any case, the disease is not dangerous and doesn't cause permanent damage, so most people simply ignore it. If needed, creams and corticosteroid lotions available without prescription can be applied on the rash.
The lesions can be reduced using ultraviolet therapy, if needed. The erythema scales or patches are most often treated due to their unpleasant aspect, using emollient lotions or desonide. If the patches appear on the trunk, coal tar can be applied on them. Two other effective products against pityriasis alba are pimecrolimus cream and tacrolimus lotion.
Some easy steps you can take to prevent the onset of pityriasis alba are simply avoiding hot climates and sun exposure and hydrating your skin at all times. This is because dry skin appears to increase the risk of developing pityriasis alba. However, sunscreen products for sensitive skin can be very effective, if you have to spend a lot of time outside. Apply a generous amount of lotion of your face and arms.
If you feel your skin becomes dry, use a moisturizer to re-hydrate it. Itchy or irritated skin can be treated with creams based on steroids but ask for medical advice before using such a product.