How to Avoid a Skin Rash in the Garden This Summer
Quick Reference: Avoiding a Garden Skin Rash
- What it is: “Margarita burn,” or phytophotodermatitis, a skin rash from plant juice or sap plus sunlight.
- The cause: compounds called furanocoumarins on your skin, then exposed to the Sun.
- Common culprits: giant hogweed, wild parsnip, cow parsnip, fig sap, and citrus like limes and lemons.
- When: most often in the warm spring and summer months.
- Avoid it: wear waterproof gloves, wash skin with soap and water fast, and slice citrus indoors.
- See a doctor if: a large area is affected, blisters spread, or a fever sets in.
You pull a few weeds, slice a lime for your afternoon drink, and a day later a red, blistering skin rash shows up on your hands or forearms. It is not always poison ivy. One painful reaction that catches gardeners off guard has a deceptively cheerful name: “Margarita burn,” known to doctors as phytophotodermatitis, or phyto-photo dermatitis. It sounds like a summer cocktail, but it is the last thing you want served on a sunny day. Here is what causes this skin rash, which plants and fruits set it off, and how to keep it from ruining your time outdoors.
The trouble starts when the juice or sap of certain plants gets on your skin while you are out in the Sun. This is worth knowing for everyone, not just gardeners, because you can brush against these plants while walking, hiking, or doing yard work. Even cutting limes outdoors and getting a little juice on your hands can trigger it. Poison ivy gets all the attention, but this reaction works by a different mechanism, and our guide to soothing a poison ivy rash covers that separate itch.
What Causes a “Margarita Burn” Skin Rash?
A combination of two things produces this type of dermatitis. Neither one alone is enough, which is why the reaction can be easy to miss until the blisters appear.
- Getting the juice or sap of certain plants on your skin.
- Exposing that substance to sunlight.
The active troublemakers are natural compounds called furanocoumarins. On their own they are harmless on the skin, but ultraviolet light from the Sun activates them, and the result is damage to the skin cells much like a chemical burn. That is why the rash lands on the parts of you the Sun could reach, and why it can show up hours after you thought you were done for the day.
What Are the Symptoms of Margarita Burn?
Margarita burn can cause a range of unpleasant, painful symptoms, including a rash, a burning sensation, inflammation, swelling, blisters, and peeling skin. It affects areas of the body exposed to the Sun, but it is not a sunburn, even though a burning sensation and skin cell damage do occur. The blisters sometimes trace the exact shape of where the juice ran, so a drip line down an arm or a handprint is a common tell.
Hyperpigmentation, a darkening or discoloration of the skin, may appear a week or two after the initial reaction. In most instances that discoloration will eventually fade on its own, though it can take weeks or months. Because the pattern looks so unusual, this rash is sometimes mistaken for other conditions, so it helps to mention any recent gardening or citrus handling if you see a doctor.
Plants, Vegetables, and Fruits That May Cause a Margarita Burn Skin Rash
Here is a list of plants and fruits that contain the toxin furanocoumarin and should be handled with caution:
- Giant hogweed (Heracleum mantegazzianum)*
- Cow parsnip (Heracleum spondylium)
- Fig sap, not the fruit (Ficus carica)
- Gas plant (Dictamnus albus)
- Queen Ann’s Lace (Ammi majus)
- Parsnip. (Other garden vegetables with low levels include carrots, celery, celeriac, and parsley.)
- Fruits: limes, lemons, and mangos.
*The most toxic plant on the list is giant hogweed. Contact with its phototoxic sap is known to deliver a severe burn. The plant can reach about 14 feet tall, and its pretty clusters of tiny white flowers resemble Queen Anne’s lace. Do not be fooled. This invasive plant is extremely toxic, and the federal National Invasive Species Information Center lists it as a noxious weed that has spread across the Northeast, the Pacific Northwest, and the upper Midwest.
How to Remove Giant Hogweed Safely
Although giant hogweed’s hollow stems are tempting to use as play pea shooters, children should be cautioned not to touch the plant. This dangerous plant should be removed from your yard with caution. Wear waterproof gloves, protective clothing, and goggles or a face shield, especially when removing taller plants. Do not touch your face or rub your eyes during the removal process.
Do not burn this plant or compost it. To destroy the plant, seal it in a black garbage bag. If any sap touches your body, wash with soap and water as soon as possible, then apply sunscreen or wear clothing that blocks sunlight. Many states ask residents to report sightings so the plant can be tracked and controlled, so check with your local extension office before you dig in.
When Does Margarita Burn Most Likely Occur?
Margarita burn, or phytophotodermatitis, occurs mostly in the warm spring and summer months. That timing is no accident. The reaction needs two ingredients at once: plant sap on the skin and strong ultraviolet light, and both peak when the days are long and the garden is busy. Late spring through late summer, roughly May into September across much of the country, is the stretch to stay watchful.
Risk also tracks with how high the Sun sits. Midday, from about 10 a.m. to 4 p.m., delivers the most intense ultraviolet light, so sap that lands on your skin at noon has far more to work with than the same sap at dusk. If you are handling any of the plants above, doing it early or late in the day gives you a margin of safety, though washing up quickly matters more than the clock.
How to Avoid a Margarita Burn Skin Rash
Anyone working in gardens and landscapes where these plants are present should take a few plain precautions:
- Wear waterproof gloves, a visor, and protective clothing when handling suspect plants.
- Wash your hands, bare arms, and legs thoroughly with soap and water soon after exposure. This step reduces the chance of any plant residue soaking into the skin.
- When spending time outside, avoid lotions, ointments, perfumes, hand sanitizers, or other products that contain citrus oils or juices.
- Slice or juice fresh citrus indoors, and wash your hands before going outside. Slicing limes in a sunny spot has sent people to the emergency room with painful blisters. Do not let it ruin your vacation or your outdoor dinner.
A little planning goes a long way here. Keep a bar of soap and a jug of water near the garden gate, learn to recognize the worst offenders on sight, and treat any unfamiliar tall, white-flowered plant with respect until you have identified it. For the itch that comes from a different plant entirely, our notes on getting rid of poison ivy and our Gardening by the Moon Calendar will help you plan safer, more comfortable days in the beds.
How to Treat a Mild Margarita Burn Skin Rash
Mild irritation can often be treated at home. Work through these steps and watch how the skin responds over the next day or two:
- Wash the affected skin areas with soap and water.
- Apply sunscreen, which may reduce the severity of the reaction.
- Avoid additional Sun exposure to lessen the severity and duration of symptoms, since sweating and heat worsen the phototoxic reaction.
- Apply a cool compress or ice pack to ease the initial discomfort. If you use an ice pack, wrap it in a thin towel, and never apply it directly to the skin.
- Apply hydrocortisone cream to reduce inflammation. Over-the-counter anesthetic sprays and first-aid creams may also aid pain relief and ease itching.
- Call a dermatologist for treatment recommendations if needed.
Seek medical attention if a substantial portion of the body is affected, especially if a fever is present. Because these blisters are a type of burn, the same wound-care basics apply, and the National Library of Medicine’s MedlinePlus guide to sunburn and skin burns is a plain-English reference for keeping the area clean and knowing when to get help.
Note: Farmers’ Almanac does not offer medical advice. Please address all medical concerns with your primary care physician.
Garden Skin Rash: Frequently Asked Questions
What is a margarita burn skin rash?
Margarita burn is the common name for phytophotodermatitis, a skin rash caused by getting the juice or sap of certain plants on your skin and then exposing it to sunlight. Natural compounds called furanocoumarins react with ultraviolet light and damage the skin cells, which brings on burning, redness, and blisters.
How long does a margarita burn skin rash last?
The initial burning, redness, and blistering usually settle within a week or two with basic care. After that, hyperpigmentation, a darkening of the skin where the reaction happened, can linger for several weeks or months before it fades on its own. Keeping the area out of the Sun helps it heal.
Can slicing limes really give you a skin rash?
Yes. Lime, lemon, and other citrus juice contains furanocoumarins, and if it lands on your skin in bright Sun it can trigger the same reaction as a garden plant. People have landed in the emergency room with blisters after slicing limes outdoors. Cut and juice citrus indoors, and wash your hands before heading back out.
How do I tell margarita burn apart from poison ivy?
Poison ivy is an allergic reaction that itches and often shows up as a line of small bumps a day or two after contact. Margarita burn is a phototoxic burn that needs sunlight to develop, tends to follow the drip or splash pattern of the juice, and can blister like a scald. If you handled citrus or tall white-flowered plants in the Sun, margarita burn is the likelier answer.
What should I do if I touch giant hogweed?
Wash the area with soap and water as soon as possible, then keep it out of sunlight by covering it with clothing or moving indoors. Do not rub your eyes or touch your face. If sap gets in your eyes or a large area of skin is affected, or if blisters and fever develop, seek medical care. Never burn or compost the plant when removing it.
When should I see a doctor about a garden skin rash?
See a doctor if a substantial portion of the body is affected, if blisters are large or spreading, or if a fever is present. A dermatologist can recommend treatment for stubborn cases and for the discoloration that follows. Farmers’ Almanac does not offer medical advice, so address all medical concerns with your primary care physician.
Deborah Tukua
Deborah Tukua is a natural living, healthy lifestyle writer and author of 7 non-fiction books, including Pearls of Garden Wisdom: Time-Saving Tips and Techniques from a Country Home, Pearls of Country Wisdom: Hints from a Small Town on Keeping Garden and Home, and Naturally Sweet Blender Treats. Tukua has been a writer for the Farmers' Almanac since 2004.
- Deborah Tukua
- Deborah Tukua
- Deborah Tukua
- Deborah Tukua
