In the Mississippi Delta, one of the poorest areas in America, residents don’t head to a specialist’s office to check their moles or fade their dark spots—they line up at Rolling Fork High School once a month. One medical expert is stationed there just 12 days a year to examine every local adult and child for any of the nearly 3,000 diagnosable skin conditions.

If that seems problematic, it is: The Delta is just one of many dermatology “deserts” in America.