What I learned about phytophotodermatitis

If life hands you lemons, do NOT squeeze them outside. When I tried that, it soured my summer in a single afternoon.

Citrus fruits, as well as several commonly found plants and vegetables, contain furocoumarins. These are organic compounds that, when exposed to UVA light, create a chemical reaction called phytophotodermatitis that kills the skin cells. As I have learned, it can be extremely painful.

Limes are often the worst culprits. And, because limes and bright sunlight often interact during the mixing of summer beverages, this condition is commonly referred to as “margarita burn.”

However, celery, wild parsnip and parsley can also cause phytophotodermatitis.

I learned all of this after I squeezed a bag of limes during an outdoor cook-off in July.

After about 36 hours, both hands and my right thigh were severely blistered.

My hands were so swollen, I couldn’t move my fingers. This reaction looked worse than any sunburn I’ve ever seen and more closely resembled a second-degree burn wound, with dozens of painful leathery blisters.

Phytophotodermatitis is a severe toxic reaction

I asked MD Anderson dermatologist Susan Chon, M.D., how fruit juice and sunshine caused something so painful.

“It’s a severe toxic reaction,” Chon says. “You have this chemical and the UV light together, and it causes immense destruction, or injury, to the skin.”

She says despite needing UV light from the sun to activate the furocoumarins, phytophotodermatitis is not a sunburn.

Chon says many people don’t know about phytophotodermatitis, and she has already seen several cases the past few months.

The reaction usually presents 24 to 48 hours after exposure and peaks around three to four days. It can take a couple weeks for the blisters to drain and the skin to peel.

Chon says people with more pigmentation in their skin could experience discoloration during the healing process.

“As it heals, you’ve injured the skin enough to where there’s what we call post-inflammatory hyperpigmentation. So, some patients will notice that they have a long-lasting discoloration of the skin, after having the initial skin reaction. However, over time this too should fade,” Chon says.

What to know about treating phytophotodermatitis

Phytophotodermatitis has to run its course; there is no cure. Treatment consists of managing pain and itching. If you’re able to catch it early, Chon recommends seeing a dermatologist, who can prescribe topical steroids to reduce the inflammation and offer wound care suggestions.

Mild cases can be treated with over-the-counter non-steroidal anti-inflammatory medications and gentle wound care, but severe blisters might require additional medication.

Chon says even a bad case of phytophotodermatitis should not increase your skin cancer risk. But cancer patients should be especially careful because several cancer medications can increase photosensitivity, allowing for a toxic reaction with much less UVA light.