Some people get pityriasis alba every summer during childhood. Even then, the pigmentation will eventually end up normal. The other extremely common white-patch condition is called tinea versicolor. Since the affected skin doesn't change color well with sun exposure, it usually becomes apparent as white patches during the summer months. The infection is chronic and recurs easily, but it causes no other health problems.
People are most susceptible to the fungus during hot months in humid areas.
Taking steroids, excessive sweating, wearing tight-fitting clothing, and chronic illness can all predispose a person to tinea versicolor, but none of these is necessary to get this mild infection. The patches of tinea versicolor can appear white, tan, or pink. The white patches look very similar to pityriasis alba. There are two good ways to tell them apart. The most reliable way is to have a doctor gently scrape the white patch, dissolve the scrapings in potassium hydroxide, and look at what is left under a microscope.