When Ellen Buchanan Weiss’ son was about a year old, he broke out in a rash — little bumps that appeared to be hives. So Buchanan Weiss did what a lot of new parents do: She turned to the Internet to find images that matched the rash she was seeing on her little boy.

But her son has brown skin, and as she scrolled through the photos that came up, she couldn’t find any images of rashes that matched her child’s — there were none on people of color. Even when she looked at the usually reliable webpages of the Centers for Disease Control and Prevention, for example, or the Mayo Clinic’s, she faced the same problem.