Pityriasis Alba
Basics
Description
- Characterized by one or more poorly marginated, pale pink, or tan/white patches and plaques that commonly appear on the cheeks, neck, and lateral arms of children and young adults
- Variants: classic (CPA: most common; endemic and atopic subtypes), extensive (EPA: teenagers, females > males, larger lesions >2 cm, trunk, shoulders, neck); pigmenting (PPA: only seen on dark skin, bluish lesions, 1.5-cm lesions, female > male, forehead, cheeks more common locations)
- System(s) affected: skin/exocrine
- Synonym(s): pityriasis streptogenes; pityriasis simplex faciei; impetigo sicca; pityriasis maculata; pseudoleucoderma atopicum
Epidemiology
Prevalence
- Ranges from 1.9% to 5.2%, more common in dark skin phototypes, male = female (some variants more common in females)
- Predominant age: 90% of affected patients are aged 6 to 12 years; rare >25 years
Etiology and Pathophysiology
- Possibly tyrosinase inhibition by Malassezia furfur, postinfectious inflammation leading to hypopigmentation, low levels of serum copper (important in melanin production) (1)
- Atopic-dermatitis-related type likely due to eczema exacerbation and postinflammatory hypopigmentation (2)
- Other implicated causes: xerosis, excessive sun exposure, inappropriate skin care, excessive washing which reduces skin defenses and protecting factors
Genetics
- Associated with carriers of a loss-of-function mutation in the gene for filaggrin, important for structural integrity and hydration of the epidermis
- Mutations in this gene are also associated with atopic dermatitis.
Risk Factors
Young age, dark skin, atopic dermatitis, low socioeconomic status, overexposure to light, frequent bathing, exfoliation
General Prevention
No known preventive measures (Sun protection may minimize visibility of lesions.)
Commonly Associated Conditions
Atopic dermatitis
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Citation
Domino, Frank J., et al., editors. "Pityriasis Alba." 5-Minute Clinical Consult, 27th ed., Wolters Kluwer, 2020. Medicine Central, im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/116458/all/Pityriasis_Alba.
Pityriasis Alba. In: Domino FJF, Baldor RAR, Golding JJ, et al, eds. 5-Minute Clinical Consult. Wolters Kluwer; 2020. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/116458/all/Pityriasis_Alba. Accessed September 7, 2024.
Pityriasis Alba. (2020). In Domino, F. J., Baldor, R. A., Golding, J., & Stephens, M. B. (Eds.), 5-Minute Clinical Consult (27th ed.). Wolters Kluwer. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/116458/all/Pityriasis_Alba
Pityriasis Alba [Internet]. In: Domino FJF, Baldor RAR, Golding JJ, Stephens MBM, editors. 5-Minute Clinical Consult. Wolters Kluwer; 2020. [cited 2024 September 07]. Available from: https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/116458/all/Pityriasis_Alba.
* Article titles in AMA citation format should be in sentence-case
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T1 - Pityriasis Alba
ID - 116458
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ED - Baldor,Robert A,
ED - Golding,Jeremy,
ED - Stephens,Mark B,
BT - 5-Minute Clinical Consult, Updating
UR - https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/116458/all/Pityriasis_Alba
PB - Wolters Kluwer
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DB - Medicine Central
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