I had a new experience this week…I tried to pull a weed from an indoor plant, and it bit back! Turned out that the weed was stinging nettle. A seed must have somehow made its way into the commercial potting soil or manure that I bought for my indoor plants.
The burning pain from stinging nettle is instant. Tiny hairs on the stem injected an irritating substance into the surface of my skin, causing a reaction so quickly that I didn’t actually pull out the weed that was growing among my plants!
Finding some relief...
Fortunately, I had grabbed for the weed with my right hand (I’m a lefty…) so I wasn’t totally incapacitated. My first instinct was to run cold water over the area and wash it with soap to try to remove the offending plant substance, and that really helped. But my next choice was a mistake that many make… I smeared the area with a numbing cream I keep on hand for first aid use, to make sure my hand wouldn’t start to burn again when it warmed up to room temperature. It happened to be an antibiotic cream with lidocaine. Bad choice, as it turned out.
The lidocaine and the antibiotics irritated the area and started up the burning sensation again with a vengeance! Ice wrapped in a paper towel applied to the area numbed it to a tolerable level and I turned to my favourite social media channel for sympathy. Fortunately, a former pharmacy student of mine who is now a doctor came to my rescue! Here were her recommendations:
Take a fast-acting antihistamine ASAP (the stinging hairs contain a substance that causes a release of histamine stimulating the reaction)
Wash off the irritating lidocaine and antibiotics, and apply a hydrocortisone cream
Continue using ice or a cold pack wrapped in a towel as needed.
Another pharmacist friend also suggested mixing a vitamin C ointment, if I had any on hand, and applying it to the area. Apparently, this is a trick used by hikers who often carry vitamin C tablets with them. I’m not sure how it works, perhaps through its anti-oxidant activity, but I wanted to try all avenues. Being a compounding pharmacist, I had some vitamin C powder (ascorbic acid), and I added a little to the hydrocortisone cream I found in my medicine cabinet. However, I must confess…being somewhat one-handed at this stage, I didn’t compound this to my usual pharmaceutical standards!
I slathered this mixture on and covered it so I could continue to cool the area with a cold pack wrapped in a towel. In case you weren’t aware, it’s important not to put ice or a frozen cold pack directly on the skin as it could cause frostbite… a freezing burn of the skin!
In a little more than 12 hours the pain and irritation were gone and my hand felt completely normal! So, here’s my advice gained through experience: learn to recognize stinging nettle (pictured above) to avoid some misery. But, if you do accidentally touch one of these plants, wash with soap and cold water then apply hydrocortisone and/or vitamin C (ascorbic acid). If you don’t have either of these on hand, they’re available at any pharmacy. If you want to try the combo I used, your pharmacist or pharmacy technician can quickly mix this up for you as I did! Ask them to use hydrocortisone 1% ointment as the base and add 5 to 10% ascorbic acid (vitamin C) to make a paste. The ascorbic acid is more stable in a non-water ointment base and will oxidize (turn brown) quickly in a water-based cream. Call ahead so they can start mixing it before you arrive and be sure to explain your emergency!
Other stinging plants
There are similarities and differences between stinging nettle and poison ivy/oak/sumac reactions. The poison ivy family of plants don’t have the stinging needle-like hairs on the stem, so the reaction takes longer to develop—usually 12 to 48 hours. And the poison ivy reaction can last 2 to 3 weeks, while stinging nettle is usually resolved within 24 hours. Poison ivy can also cause blisters.
But the treatment is similar. Wash the area well with soap and water. Take an antihistamine (preferably a fast-acting one like cetirizine/Reactine) and apply hydrocortisone cream to the area to reduce irritation and itchiness. With poison ivy you also need to be careful with any clothing or items (including pets!) that might have been in contact with the plant. The irritating oil can remain active for months, even longer than a year, and can cause a rash later if it contacts the skin. Handle items carefully (best to wear disposable gloves and turn them inside out when removing them) and wash well with soap and water.
It’s important to avoid scratching, too, as this could introduce infectious bacteria into the skin. If any lesions develop pus or other signs of infection, an antibiotic might be needed, and this would be a reason to see a doctor. Also see a doctor if a large area is affected as cortisone tablets might be preferred to the cream.
Learn to recognize poisonous plants
Want to avoid poison ivy? My daughter advises, “leaves of 3, let it be”. Both poison ivy and poison oak have leaves that grow in groups of three’s… while stinging nettle can be recognized by its spiky pairs of leaves. And never burn these poisonous plants—the toxin can be inhaled in the smoke causing a dangerous respiratory reaction!
One last tip: jalapeño peppers can cause a similar fiery reaction if you chop them with bare hands…always wear protective gloves when trying out that yummy salsa recipe.
Meanwhile, I’ll be stocking up on some gardening gloves to protect my hands when pulling weeds in the future!!
References:
Stinging Nettles -- Ministry of Health, New Zealand
Poison Ivy Rash -- Mayo Clinic
Relief from poisonous plants while on the trail -- Outdoor Herbivore Blog
