Who Knew You Could Be Allergic to Agave Americana?

Until this summer, my only known allergy was to the Australian silk oak, Grevillea robusta, which I wrote about in the July 2020 issue of TCI Magazine (Safety Forum: “Beware the Australian Silk Oak.” Quite recently I suffered another, albeit less serious, case of contact dermatitis from direct exposure to the sap of an Agave americana, or century plant.

Desert woodrat, Neotoma lepida, in a century plant.
Desert woodrat, Neotoma lepida, in a century plant.

This species is not native to the Sonoran Desert where I live and work but is well adapted to our climate and quite widely dispersed here as an ornamental landscape plant. A client had us remove one from their front-yard area, as they have ongoing issues with Neotoma lepida, the desert woodrat, commonly known as a pack rat.

These rodents will use century plants not only as a food source, but also a nesting area. Though pack rats are an important part of the desert ecosystem, when they move in close to residences they tend to get into all sorts of trouble, perhaps most notoriously eating the wiring out of people’s cars. Managing their available habitats farther out in the desert is best practice to ensure they stay there!

Man next to a Agave americana tree
The author with an Agave americana, or century plant. All photos courtesy of the author.

These agave can weigh up to 1,200 pounds, and they produce a large flower stalk at the end of their life cycle that can grow up to 30 feet tall. This specimen was only about 600 pounds, but regardless, if you have to remove one manually, the easiest way is to cut off the “leaves” with a handsaw and use a chain saw to section up the “heart.”

There are many known cases of people having allergic reactions to different agave species. Before this, I had been in contact with Agave americana countless times, but I’d only ever experienced minor irritation on exposed skin areas that came into contact with this plant’s sap.

An Agave americana, or century plant.
An Agave americana, or century plant.

After removing the leaves, I put myself in a left-handed chain-sawing position, with my left hand on the throttle and my right hand on the handlebar, standing on the right-hand side of the saw.

This is not a recommended chain-saw-operating position, but I did this in an attempt to stay as far as possible from the spray that comes off the bar when you section up the larger heart pieces. I was wearing short sleeves, and managed to get some of the sap on my left arm.

After I had finished my three to four cuts, I started to feel a burning sensation on my arm. I immediately removed my chain-saw-protective pants and my gloves and washed myself off with water from a nearby hose bibb.

My employee, Peter Fortune, was with me that day handling the leaves and heart sections after I cut them. He was wearing long sleeves, but volunteered to have a small amount of sap put on his forearm to see if it affected him as well. He experienced the same symptoms, though only in the isolated area where we directly applied the sap. I heard back later that his wife thinks we both might have below-average cognitive abilities.

In the following days, I developed a rash similar to a first-degree burn, which cleared up on its own after four to five days. When I was younger, I used to get agave sap all over myself and never had anything like this happen, so I don’t know if it’s a function of aging or if perhaps this was just a very potent specimen!

arm with rash
I developed a rash similar to a first-degree burn.

In the future, I definitely will be taking further precautions to limit my own and my employees’ exposure to the sap of this species, as we have learned it can present a rather significant hazard.

Victor Riquelme is the owner/operator of Big Olive’s Property Maintenance/Big Olive’s LLC, in Tucson, Arizona.

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