Have a Post-Vacation Skin Rash? It Might Be Phytophotodermatitis

I went to Tulum, Mexico at the beginning of this year, and it was a vacation to remember. Then, when I got home, I realized I brought back more than just a sun-kissed tan and great memories. I noticed brown and red splotches on my left thigh, left arm, and tiny brown dots climbing up my arms starting at my thumbs. As someone who constantly examines her skin to make sure there's nothing new on there I should be worried about — I was worried. I sent pictures to everyone I trust, including my mom, who told me to book an appointment with a dermatologist as soon as possible. I did, but I had an entire weekend to dwell on what it might be, so I set out to surf the web to hopefully calm my anxiety.

From searching "sun exposure in Mexico" to "brown spots after sun exposure" for what felt like hours, I finally found something that seemed to explain what was happening on my skin: phytophotodermatitis, a strain of dermatitis that happens when the juices from fruits like limes and lemons come in contact with your skin, followed by intense sun exposure.

Now, I was definitely eating 85 tacos a day and squeezing 3 times the normal amount of limes on them, but I was also diligent about sunscreen on my face and on my body because the sun in Tulum is intense being closer to the equator. Later, when I finally met with my dermatologist, I found out that it didn't necessarily matter how much sunscreen I was using — I still had lime juice on my body while I was lounging on the beach in the sun.

Turns out, there is much to learn about best practices to keep in mind during sun exposure, especially familiarizing yourself with potential side effects of phytophotodermatitis, like hyperpigmentation. Keep reading to learn more about the skin condition, what causes it, and how to treat it at home.

I arrived to see dermatologist Anna Karp, MD, at SINY Dermatology in Brooklyn a few days after finding the blotches, which at that point started to look more red than brown, and she confirmed my research results.

"Phytophotodermatitis is a rash that we develop when certain foods or plants that touch our skin react with the sun," she tells POPSUGAR. "These plants all contain light-sensitizing substances called furanocoumarin. Commonly we see it when people are on vacation, having drinks or foods with lime, then lay out in the sun."

The way it manifests on the skin can be different depending on the person, but there are a few things to keep an eye out for. "Usually it presents as a strange streaky shaped rash, not a perfect circle like we see in other rashes," Dr. Karp says, adding that what was happening on my thigh was a "perfect example" or phytophotodermatitis.

In my case, it was limes that caused phytophotodermatisis to appear on my skin, but like Dr. Karp mentions, this isn't the only fruit or food that contain light-sensitizing furanocoumarin, thus triggering a reaction. "Other foods that can cause it include figs (from the sap, not the fruit), parsley, parsnip, bergamot oranges, and celery as well as certain plants and weeds," says Dr. Karp.

The key difference here, compared to other forms of dermatitis, is that the exposure to sun after touching said food is what ultimately causes the irritation. "It's safe to say if it's a very sunny day, even 10 minutes outside will cause a reaction," she says. "It is also made worse the longer the lime was on your skin, absorbing into it." The furocoumarin substance interacts with the DNA in our skin cells and when the sun hits it, it can cause damage that usually takes 24 hours to develop into a rash.

As for how to avoid rashes in the future, especially if you love beaches and the sun, Dr. Karp says to "be mindful, if you do get lime on your skin, to wash it off quickly to avoid this rash." Citrus has been and still is used by many to lighten dark spots, hair, and chemically exfoliate, but that is ill advised. Lemon juice has an extremely low pH and can be damaging and irritating to the skin.

Dr. Karp recommends you see a dermatologist as soon as you notice anything different on your skin, especially after coming back from a sunny vacation. "The rash can blister so if you get it, you want to get an anti-inflammatory cream like hydrocortisone on it right away," she says. "It can also leave behind post-inflammatory hyperpigmentation, which you can start treating once the redness of the initial rash is gone."

You can get over the counter Hydrocortisone 1% ($10) at the drugstore, or you can get a higher dose prescription from your doctor. Depending on where your rashes appear, you may also want to stay away from fragranced beauty products, like body lotion, body wash, or perfume, as it can potentially contribute to more irritation. Instead, stick to fragrance-free options that are gentler on skin, like the Curel Fragrance Free Body Lotion ($12) or the Aveeno Daily Moisturizing Body Lotion with Soothing Prebiotic Oat ($10).

As for me, my skin is definitely getting better. I can still see traces of hyperpigmentation that the phytophotodermatitis left behind, so I will be making another appointment with Dr. Karp to treat it and will always make sure to either eat the foods she mentioned in the shade, or take a dip in the ocean as soon as I am done with my birria tacos.