Why do I get white spots on my skin in the summer and how can I treat them? A dermatologist

Is your tan looking a little patchy this summer? Are you noticing small white or reddish spots scattered across your shoulders, back, chest, or arms — spots that seem to appear out of nowhere and just won’t tan along with the rest of your skin? You’re definitely not alone, and there’s a dermatologist-backed explanation for exactly what’s happening.

There’s nothing quite like catching a glimpse of your reflection and seeing that golden summer glow after a day at the beach or a lazy afternoon in the sun (sunscreen included, of course — we never skip that step). It’s one of the simple joys of the warmer months. But sometimes, instead of the smooth, even tan we’re hoping for, our skin has other plans.

Some people begin to notice small white or reddish patches appearing on their skin after sun exposure, making their tan look blotchy, spotty, or uneven. It can be surprising, a little worrying, and honestly kind of frustrating when you were just trying to get some color. Dr. Sandra Lee — a well-known American dermatologist, often recognized from her popular skincare content online — recently broke this exact issue down in a short video, explaining both the cause and the treatment in simple terms.

So What Exactly Causes These White Spots After Sun Exposure?

Here’s something a lot of people don’t realize: our skin isn’t just skin. It’s actually home to thousands of tiny microorganisms — bacteria and yeasts — that live on the surface at all times. Together, they make up what’s known as the skin microbiome, and under normal circumstances, this ecosystem stays balanced and causes zero issues. Most of us go our entire lives without ever thinking about it.

But certain conditions can throw that balance off. Heat, humidity, sweat, oily skin, and — you guessed it — extended sun exposure can all create the perfect environment for one particular type of yeast, called Malassezia, to grow more than usual. This yeast lives on everyone’s skin naturally, but when it multiplies excessively, it can interfere with the skin’s normal pigmentation process.

The result? A condition called tinea versicolor, sometimes also referred to as pityriasis versicolor. It causes patches of skin to become lighter or darker than the skin surrounding them. And here’s the part that makes it especially noticeable in summer: when the rest of your skin tans and darkens from sun exposure, the affected patches don’t tan the same way. They stay pale, or sometimes take on a slightly pink, red, or brownish tone instead — which creates that uneven, “spotty” appearance so many people are frustrated by.

Is Tinea Versicolor Contagious? Is It Dangerous?

This is usually the first question people have, and the answer is reassuring: no, it’s not contagious, and no, it’s not dangerous. It has nothing to do with hygiene, and it’s not something you “catch” from someone else or pass along through contact. It’s simply an overgrowth of yeast that’s already naturally present on your own skin.