Pityriasis rosea is a skin condition that causes a “Christmas tree” rash. It starts with one patch, known as the “mother patch,” and branches out with smaller “daughter patches” on other parts of the ...

Before the pandemic began, D.C. dermatologist Adam Friedman routinely treated patients with pityriasis rosea, a temporary but often unbearably itchy skin rash that can last several months. There are ...