Tinea Versicolor:
Teen information

If you suspect that you have tinea versicolor, you might try an over-the-counter antifungal cream such as terbinafine, clotrimazole, or miconazole. An over-the-counter shampoo containing selenium sulfide can be used as a lotion by applying it to the affected areas overnight and rinsing it off in the morning. However, if the condition does not seem to be getting better after 2 weeks of daily treatment, see a dermatologist or another physician for evaluation.

If you have been treated for tinea versicolor, avoid wearing tight, restrictive clothing. Also, sun exposure may make the light-colored areas more apparent, so avoid sun exposure or wear sunscreen until the spots have returned to their normal color.
If the above self-care measures do not work or if you develop a widespread rash that seems to be getting worse, see your doctor.