A recent edition of the Parenting newsletter from The New York Times focused on pinworm infection. It’s one of the most common human intestinal worm infections, with about 40 million people infected with pinworm in the United States.

Adam J. Ratner, MD, director of the Division of Pediatric Infectious Diseases and pediatrician at Hassenfeld Children’s Hospital at NYU Langone, discusses the symptoms, which can be upsetting to parents if they don’t know what to look for. The primary sign is intense itching around the anus, particularly at night.

Luckily, although pinworm is uncomfortable, it’s not serious, even if you don’t catch it early. “Unlike a lot of other parasitic infections, you don’t have long-term effects,” Dr. Ratner says. Over-the-counter and prescription medications are available for treatment.

Read more from The New York Times.