I got dandruff pretty late in life. It took me a while to realize it has to do with my psoriasis, which brings many other ailments (“Psoriatic Arthritis,” July 23, 2012). Also, it took me several years to realize that I get dandruff during the cold months only. It disappears completely during the warm months. Ever since the beginning of the turn of the millennium, I use Head & Shoulders during the winter and Johnson & Johnson baby shampoo during the summer (“How Conservative Am I?” February 17, 1998). But I just got dandruff in the middle of July. And it is unseasonably wet and cold, indeed. Climate change, of course. As it turns out, even my psoriasis is confused about the weather.