BY KENNETH SETZER
As published in the Miami Herald, 11/5/15.
Ah the wonders of gardening! The health benefits of being outdoors, growing your own food, breathing in all that good mood-elevating Mycobacterium vaccae soil bacterium or just contemplating the natural beauty of it all! So why do I come in from the yard scraped, red and swollen?
Poison ivy is fairly common throughout South Florida.
Contact dermatitis, described by the Mayo Clinic website as “a red, itchy rash caused by a substance that comes into contact with your skin,” seems to be caused by just about anything your skin finds irritating. I often come inside with itchy, raised red lines across my forearms. What specifically causes this I still haven’t discovered, but it’s obvious my skin is reacting to a plant.
As cumbersome as it is, wearing gloves is a major help and you get used to it fast. This avoids the many little scrapes and cuts you are likely to get cutting, pruning, trimming or simply pulling weeds, and it keeps contact dermatitis at bay.
Leaves can cut and irritate, so wear garden gloves.
I’ve grabbed a handful of Ponytail palms (Beaucarnea recurvata) leaves and gotten sliced by their sharp edges. Now I am starting to suspect ponytail palm leaves are also causing the raised irritations across the forearms. A long-sleeved shirt is in order, but unbearable until the weather cools.
Some common irritating plants to watch out for are from the euphorbia — or spurge — family, including poinsettias, the copper plant (Euphorbia cotinifolia), crotons, and many ornamental succulents often mistaken for cacti. Euphorbia’s milky latex sap is caustic.
One of the most infamous euphorbs, the manchineel tree (Hippomane mancinella) is found in South Florida and the Caribbean. All of its parts are reportedly very caustic, toxic and just plain unfriendly. The tropical Plumeria and other Apocynaceae family members are also a potential irritant, if their latex contacts the skin. Handle with gloves.
Moses-in-the-cradle—incredibly common, possibly irritating
I love cacti, but caring for them is comparable to bathing cats: You are bound to experience some pain. Cactus spines are easy enough to see and avoid, but many cacti have glochids, small clusters of hairlike projections that apparently exist to dissuade herbivory. And pity the poor animal that eats a cactus pad with glochids! They are nightmarishly difficult to extract from the skin because they are so tiny. You will feel them, like a pin prick, but extracting them with a tweezers under a good light is not easy. Nasty little things have even gotten through my thick leather work gloves.
Poison ivy, the bane of the outdoors, thrives locally. Toxicodendron radicans might be encountered on a nature walk or around your neighborhood. In the Anacardiaceae family along with mangos, cashews and Brazilian pepper, poison ivy affects everyone differently. My father used to tell a tale of cutting himself on poison ivy, with the allergen, called urushiol, thus entering his bloodstream to a most unpleasant effect. But dad liked to embellish.
Philodendrons contain irritating needle-like raphides.
The unholy trinity of “leaflets of three” helps identify poison ivy along with a reddish, “hairy” stem, but it can be quite variable in appearance. It often grows as a vine on the ground or up a tree. Poison oak and sumac are present in central and northern Florida. Poisonwood (Metopium toxiferum), though restricted to South Florida, is not likely to be encountered while doing yard work, unless you live in the Keys.
Even the common lowly oyster plant, or Moses-in-the-cradle, (Tradescantia spathacea) can cause contact dermatitis in sensitive individuals.
The classically tropical aroids, including philodendrons, contain oxalate crystals, which can create needle-like structures called raphides, obviously irritating against the skin, worse if eaten.
It’s ideal to avoid these unpleasant conditions in the first place, but if exposed to an irritant like poison ivy, you will need to wash your skin, clothing and anything that came into contact with the irritant. But if the reaction is extreme, the American Academy of Dermatology (www.aad.org) recommends seeking emergency medical treatment.
Everyone reacts differently to these and other irritants, so just take a little precaution and yard work’s benefits will continue to vastly outweigh its risks.