It’s the season for flannel pajamas, wool blankets, and cozy, billowy bedding. But if you’re dealing with psoriasis, feeling comfortable in your own skin is a challenge—let alone sleeping between winter’s warmest fabrics. “Psoriasis is a chronic autoimmune condition that causes the rapid buildup of skin cells,” says Manhattan dermatologist Ellen Marmur, M.D., founder of MMSkincare. This buildup of cells can form scaling on the skin’s surface, as well as inflammation and redness, Dr. Marmur says. “Choosing bedding wisely is important because certain fabrics and detergents can make the condition worse,” she says.