The Case
A middle-school aged boy presents with a slightly pruritic rash that started along the side of his chest, but then soon spread to encompass several dozen similar lesions across his torso, especially his back. he has had no other symptoms, including fever or upper respiratory complaints. There are no new food, personal care product, or animal exposures. The rash – after being present for approximately 10-12 days is shown below.
The initial lesion is in the center of the following image:
Here are some other pictures of the rash:
The Diagnosis
This is pityriasis rosea. The rash is also called the rose-colored scale. It is also called pityriasis circinata, roseola annulata, and herpes tonsurans maculosus. This is an acute and self limited papulosquamous rash. Classically you’ll see the initial “herald patch,” followed by scaly oval patches that erupt over approximately two weeks often in a Christmas-tree like pattern on the trunk and proximal extremities. The herald patch is seen in 50-90% of cases, and pruritus is severe in 1 in 4 patients. The cause for most cases is viral, Human Herpes Virus 6 and Human Herpes Virus 7 have been implicated. The eruption usually lasts for 6 to 8 weeks. There were no other symptoms other than the rash. Interestingly this patient’s younger brother had a similar rash but didn’t complain as much. Atopy is also associated with a higher risk of developing pityriasis rosea.
Management
Supportive care is really all you need. If it is super itchy and interfering with sleep and daily life antihistamines and emollients are recommended. Since it is self-limited it will go away on its own and the lesions are non-scarring. Macrolides and acyclovir may lead to faster resolution of lesions and help to relieve pruritus in someone with sever symptoms. Narrowband ultraviolet B therapy could also help by altering the skin’s immune response. So I guess send him outside. of note – pityriasis rosea during the first trimester of pregnancy can be dangerous and may cause premature delivery and/or fetal demise.
