Photo quiz: what causes brown spots on feet?

What causes brown spots on feet? In the summer, we see kids with these spots on their feet or hands. Read on for the answer behind the mysterious spots.

Every child with a lemonade stand hopes for hot sunny days to drive in customers. But if your kids squeeze fresh lemons for their stand, make sure they wash their hands after squeezing the lemons. Otherwise, after a sunny day, your child’s hands may turn out looking like this kid’s feet. The juice of some fruits or plants will cause a dark discoloration of the skin if exposed to sunlight.

This reaction, called phytophotodermatitis, usually starts a day after the juice comes into contact with the skin. Redness and mild blistering eventually leads to a discoloration, like those brown spots on feet, which can that can last for months. Citrus fruits are the most common culprits, but wild parsnip, wild dill, wild parsley and buttercups also cause the photosensitivity. Often the initial redness and blistering is missed. The kid in the photo was walking in bare feet on leaves near an apple tree. So now you can tell your kids not to walk barefoot outside to prevent stepping on a bee, to prevent contracting poison ivy, and to prevent phytophotodermatitis!

Makes you think about holding off on fresh lemons and using powdered lemonade mix…almost.

Naline Lai, MD and Julie Kardos, MD
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