If you’re dusting flakes off your shoulders enough to instinctively avoid your black shirts, then you might think you have an especially stubborn case of dandruff. But there’s a chance you could actually have scalp psoriasis, a form of the chronic skin condition that extends to the scalp, hairline, and ears. Scalp psoriasis has a lot in common with dandruff, also known as seborrheic dermatitis; the two conditions involve scaly or dry patches on the scalp as well as flakes. In fact, they’re so similar that “we sometimes even use the term ‘sebo-psoriasis’ to describe overlap between seborrheic dermatitis and psoriasis,” says Joseph Merola, MD, a board-certified dermatologist at UT Southwestern Medical Center. But that mistaken identity can keep you from using the right treatment and getting some relief. With that, here’s how to tell them apart. Why psoriasis and dandruff get confused Itchiness, flakes, inflammation: These are typical signs of both psoriasis and dandruff. But you can find subtle clues to tell them apart, since they can differ in their appearance, location, and severity. …