What Is Pityriasis Alba?
Pityriasis alba is a type of dermatitis that usually occurs frequently in childhood and adolescence, especially in children and in young people with dark complexions. In the past, it was known by names such as erythema streptogenes, pityriasis streptogenes, and impetigo furfuraceus.
Although it usually causes some concern among parents, pityriasis alba isn’t a serious health problem. Actually, it’s a benign disorder that also has a treatment.
Pityriasis alba is characterized by causing white skin spots, but these spots aren’t white at first.
At first, the injured areas are reddish in color and peeling, and the spots have rounded or oval edges. As they disappear, they turn a light color, which is finally defined as white. This process is known as hypopigmentation.
- The patches redden easily in sun exposure, but they don’t tan. They are usually 1 to 5 centimeters (up to 2 inches) in diameter.
- When the skin is exposed to the sun, it darkens except for the patches, which is why they become more noticeable.
- For all the above, it’s essential to use sun protection on a daily basis.
Although in the past it was common to think that its cause could be a bacterial infection, over time it was proven that this was not the case. The lesions do not respond to antibiotics and their appearance, from the histological point of view, wasn’t consistent with that of an infection.
Currently, the cause of pityriasis alba is unknown. Some people consider that it could be linked to atopic dermatitis and others maintain the hypothesis that it could be related to vitiligo.
Its appearance has also been associated with factors such as poor body hygiene, lack of nasal cleansing, poor hydration, dry skin, overexposure to the sun, and others. However, no specific relationship has been proven to date.
Medline Plus experts indicate that in order to reach a diagnosis of pityriasis alba, a physical examination in consultation is usually sufficient. However, in some cases, the doctor may ask for some tests (such as a potassium hydroxide test, and, rarely, a skin biopsy) to rule out other problems, such as:
- Atopic dermatitis
- Diseases that cause post-inflammatory hypopigmentation
Even though, in many cases, pityriasis alba goes away on its own, it sometimes requires treatment. It’s important to note that this isn’t curative, it’s simply to take care of the skin and prevent complications.
On the other hand, it must be borne in mind that just as sometimes it can disappear and not appear again, in others it can reappear later.
Treatment includes the following measures:
- Daily sunscreen application
- Use of a topical retinoid and PUVA
- Application of moisturizing creams with emollient ingredients (to relieve dry skin and flaking)
In some cases, to prevent complications (such as skin atrophy), the doctor may prescribe a mild topical antifungal and steroid for a set period of time (usually short).
Other treatment options that the doctor may indicate in some cases are the following:
- Immunomodulator (to reduce inflammation)
- UV light treatment (to control inflammation)
- Laser treatment
- Medications (to control more severe dermatitis)
Just as the origin of pityriasis is unknown, how to prevent it is also unknown. However, the use of sunscreen on a daily basis continues to be highlighted as a measure to prevent patches from becoming more noticeable.
Finally, the most important thing when treating pityriasis alba is to adhere to the doctor’s recommendations and, if in doubt, consult with them. It isn’t advisable to try to modify the treatment on your own or to try lightening products, as this could be counterproductive.
- Rey JP. Alteraciones de la pigmentación cutánea. AEPED [Internet]. [cited 2021 Jul 10]; Available from: https://www.aeped.es/sites/default/files/documentos/pigmentacion.pdf
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Mex 2010;54(2):67-71. https://www.medigraphic.com/pdfs/derrevmex/rmd-2010/rmd102e.pdf
- Pitiriasis alba | Dermatología. Atlas, diagnóstico y tratamiento, 6e | AccessMedicina | McGraw Hill Medical [Internet]. [cited 2021 Jul 10]. Available from: https://accessmedicina.mhmedical.com/content.aspx?bookid=1538§ionid=102303700