(Reuters Health) - Gardeners caring for plants in the Euphorbia genus should be careful about handling the toxic sap, according to a new report.

More than 2,000 species of euphorbia exist, including succulents like certain cacti, tropicals like Poinsettia, and flowering shrubs and trees, both evergreen and deciduous. Particularly popular are plants known as spurges, which tend to be drought- and deer-resistant.

Euphorbia plants produce a white latex sap that can vary in chemical makeup and toxicity. Since all of them require pruning, gardeners should remember to wear gloves and eyewear when handling them.

In particular, getting sap in the eye can cause severe burning, light sensitivity, swelling, blurry vision and watery eyes.

In the journal Eye, Katherine McVeigh of the Bristol Eye Hospital in the UK describes a patient who came to her with inflammation and pain, but she couldn’t figure out at first what was wrong.

“I felt unnerved when a patient presented with an excruciatingly painful eye and minimal history,” she wrote. “She reported gardening but denied use of any chemicals.”

Eventually, McVeigh attributed the problem to contact with euphorbia in the patient’s garden.

With particularly toxic euphorbia sap, severe cases have included burns in different parts of the eye, ulcers on the cornea, and blindness, she notes in her report.

If sap does get into the eye, wash the eye with water immediately, McVeigh advises.

“Irrigation of the eye is key when any chemical injury occurs, as it not only dilutes the substance in question but helps to reset the pH of the ocular surface,” she told Reuters Health by email.

Dr. David Fleischman of the University of North Carolina at Chapel Hill, who wasn’t involved in McVeigh’s report, has treated severe euphorbia cases in the United States and is researching the public health issue of euphorbia plants.

“The most important point is raising awareness to the general public and gardeners and to those in the medical community who may first encounter these patients,” he told Reuters Health by email. “Cases that are caught earlier, treated appropriately, and given close follow-up will fare much better.”

Treatment for euphorbia is directed at rebalancing the pH in the eye, McVeigh said. Washing out the eye and using lubricants, topical antibiotics, eye patches and bandage contact lenses are the best options currently.

“It is also important that parents educate their children since many injuries that occur in the pediatric population are through play within the garden,” she said.

“Know the plant species you’re working with, and do not rub your eyes without carefully washing your hands after gardening,” Fleischman said. “Remember that wiping sweat off of your brow could sometimes inadvertently bring noxious plant matter to the eye, even in the most well-meaning gardeners.”

Today McVeigh tells doctors and nurses, If there are few clinical signs to diagnose an eye problem, think euphorbia and ask about the patient’s gardening history.

SOURCE: go.nature.com/2fP3nvR Eye, online September 22, 2017.