Schedule says “5.5 yo with rash”. I walk into the room to find a very friendly mom with twin daughters at age 5. The girls are both very well behaved in the exam room, and mom is very attentive and a great historian. Mom reports a rash that started about 2 days ago on patient’s head and neck. Over the past 24 hours the rash spread down the chest and torso and now to the arms and legs. Pt reported to mom that the rash is itchy. Child was at the time in a summer camp along with her twin sis. She may have had a slight case of the sniffles with a subjective fever at home 2 days ago that since has resolved.
No sick contacts.
No recent travel.
No insect bites.
No significant PMHx.
No current meds.
No other sxs at this time.
Vitals were unremarkable. Temp was 99.1.
On exam I see no rash on the scalp.
No oral lesions.
She has a reticular rash on the face and neck.
Has the same rash on the extensor surfaces of the extremities.
Has what appears to be wheels on the deltoids that aren’t excoriated.
I go to my office to think and research. I decide to google “cephalo-caudal reticular rash child” and the page is lit up with “Parvo B-19”. I go on uptodate.com and read up on Erythema Infectiosum to be sure. I google the images and yeap, I’m sure it’s Fifth Disease. I go back in and notice the twin sister has same rosy cheeks. I tell mom that most likely she will develop similar symptoms in the next few days. And sure enough 24 hours later her twin had the exam same thing. The wheels threw me off, but classically with urticaria the wheels would disappear within 24 hours and these hadn’t changed in 2 days nor were they excoriated.
What was your first impression and how do you go about diagnosing a child with a rash?