pityriasis
noun
pit·y·ri·a·sis
ˌpi-ti-ˈrī-ə-səs 
: any of various skin conditions of humans or domestic animals marked by dry scaling patches of skin
Examples of pityriasis in a Sentence
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Several other skin conditions can cause similar-looking rashes, like Lyme disease, pityriasis rosea, psoriasis, and nummular eczema.
—
Sarah Bradley, Health, 3 Aug. 2024
Tinea versicolor, clinically known as pityriasis versicolor, is a fungal skin rash caused by an overgrowth of a certain yeast that is naturally present on your skin.
—Anna Giorgi, Verywell Health, 24 July 2024
What is pityriasis rosea?
—Lauren Caruso, Allure, 17 Aug. 2021
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Sarah Bradley, Health, 3 Aug. 2024
Tinea versicolor, clinically known as pityriasis versicolor, is a fungal skin rash caused by an overgrowth of a certain yeast that is naturally present on your skin.
—Anna Giorgi, Verywell Health, 24 July 2024
What is pityriasis rosea?
—Lauren Caruso, Allure, 17 Aug. 2021
Cite this Entry
“Pityriasis.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/pityriasis. Accessed 30 Oct. 2025.
Copy CitationMedical Definition
pityriasis
noun
pit·y·ri·a·sis
ˌpit-ə-ˈrī-ə-səs
plural pityriases
-ˌsēz
1
: any of several skin diseases marked by the formation and desquamation of fine scales
2
: a disease of domestic animals marked by dry epithelial scales or scurf due to alteration of the function of the sebaceous glands and possibly associated with digestive disorders
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