Intermediate
Technical
In the Industry Vocabulary Test
Pityriasis Rosea
Pronunciation: pit-ih-RY-ah-sis ro-ZEE-ah
Self-limiting viral exanthem characterized by a herald patch followed by secondary eruption in a Christmas tree distribution.
Full Definition
Pityriasis rosea is a common, benign skin condition affecting children and young adults, likely caused by human herpesvirus 6 or 7. It typically begins with a single herald patch, followed 1-2 weeks later by multiple smaller oval lesions with a distinctive Christmas tree pattern on the back. The rash is usually mildly pruritic and resolves spontaneously within 6-12 weeks. Differential diagnosis includes secondary syphilis, tinea corporis, and drug eruptions.
Usage
Usage note: Always consider secondary syphilis in the differential diagnosis.
In Context
- "The herald patch and Christmas tree distribution confirmed pityriasis rosea." — Dermatology consultation
- "Pityriasis rosea was diagnosed based on the characteristic appearance and distribution." — Physical examination note
Also known as
Christmas tree rash
Don't confuse with
tinea corporis
secondary syphilis
viral exanthem