Dictamnus alba ( commonly called 'Gas Plant') can cause a nasty poison ivy type of rash.

The sap of most Euphorbias can cause a rash.

Euphorbias were my first thought also. I get rashes from junipers. I guess it could be an individual thing - not everything affects everyone the same way. She could have had a reaction to a plant that doesn't normally or widely cause reactions in others.

:)
Dee

I get a 'Poison Ivy like' rash from Daffodil greens.
Yew bushes too can cause it.
Nina

My mother would get a rash from sweet alyssum...I get a rash from the leaves and skin of zucchini.
And then there's stinging nettle.
Linda C

I think Monkshood has toxic sap too.

Speaking of plant rashes, I recently discovered that a woodland weed that I have been trying to manage, Jewelweed (impatiens capensis), often grows near poison ivy and its sap is used as an antidote for poison ivy rash. Mother nature at her best!

I used to have poison ivy in those woods years ago. It was eradicated and now the Jewelweed is filling the woods. Very invasive... its trying hard to get out to everything else... but that's another story.

Hops vine does it for me. It used to leave long welts on my skin like I got whipped until I got smart enough to cut my vine back while wearing a sweater.

I get rashes from anything that has pricklies on it,this includes tomatoes,squash,pumpkins,cukes,etc.

I get a rash from gaillardia, gas plant, and euphorbias. The euphorbia rashes are really horrible and left scars on my legs. It's like a chemical burn for me.

Then again, I am allergic to just about everything.

Virginia Creeper can also cause a rash in some people.

Thanks everyone. I'm printing this out to give her. She can see if any of the mentioned plants are in her garden and be very careful around them.

Some black eyed susans...I want to say it's the annual ones but I think even my perennials sometimes, have little spiny hairs on them that can cause a rash, too. :) When the annual ones died in the fall and I was collecting seeds to reseed the wildflower bed, I got a few splinters, too!

I am not an allergic person but poison ivy is a bad one. I also got a tremendous rash that lasted for many weeks from gas plant some years ago. Didn't hurt, didn't itch--just looked horrible. It was from the sap, not the leaves or flowers.

Junipers also bother me when pruning them, not just by brushing by them.

One I've never encountered personally but has become a problem in this part of the country is giant hogweed. This one can be quite dangerous and I was very surprised to see someone seeking seeds of it on another forum. You can Google it and read about its charms for yourself.

One more for you: my Anthemis irritates my skin and gives a short-term rash -- usually gone the next morning.

Bind weed breaks me out and DD can't let most decorative tall grass touch her skin. I think any plant can be an allergen of some sort to a person, it just depends on the person.

Yarrow gives me a rash. Am I the only one?

English Ivy gives me a terrible rash - more specifically, the sap - casual contact with the leaves is fine. Have to wear gloves when I tear it out several times a year from the beds.

- Steve

The only time I've ever had a plant related rash is the time I was cleaning Hollyhocks at the greenhouse I work at. I was pulling dead leaves of and cutting them back and I was wearing gloves. But everywhere those prickly leaves touched the skin under my arm, from wrist to elbow, I had these nasty looking marks. Someone else mentioned their rash looking like whip marks, and that's how this was. It turned bright red, and then the skin hardened over like a burn. It took a couple of months for the redness to go away, and it looked awful. There are still a few faint scars from it. Now I am leary of any plant with similar hairy leaves.

One of the fine leaved miscanthus grass "Morning Light" irritates my forarms when I come in contact with it.
Also a friend of mine cannot come in contact with cone flowers. The same reaction with red arms. Go figure.

None of the other grasses have this effect on me.

Privet gives me an itchy, burning, welty rash, although thankfully it doesn't last too long.

Ruta graveolens, or rue, can cause a rash if you come into contact with the sap from cut stems. It may also be photosensitive, and be made worse with exposure to the sun.

I have also heard of plants in the family Umbelliferae, such as fennel, can also cause a rash or irritation.

I've read the same thing about ruta and bronze fennel, but since I always treated them with circumspection, I never actually experienced it.

Junipers do it to me, but not much else. I never went NEAR my euphorbia!

What my allergist said to me:

Anyone can be allergic to anything at anytime.

Raspberries will give me a rash but it usually doesn't last more than a few hours. Your friend should try to avoid whatever it is since it will probably get worse with repeated exposure.

Whenever my husband and I pull out dead Zinnias, we both get a rash and itch. Now we wear long sleeves!

Milkweed gives me a nasty blistery itch.

Hollyhocks are hairy and they make me itch bad! I know that thrips are gone here, but they are tiny bugs that like to swarm on bright colored flowers, and they bite, and itch too! No see ums do the same thing.

My DD had a rash from pulling lots of Honesty in the yard a few weeks ago. It was all over her forearms but gone by the next morning.

I am in agreement with "anything that has prickley hairs the foliage or stems" (i.e. tomatoes,squash,pumpkins,cukes). I get the intense itching, then the rash, and if I don't wash right away the "whip marks." What a bummer...who wants to garden in the hot weather with long sleeves. Zyrtec doesn't even touch it.

Chrysanthemums(mums).

Nightshade vine.

Zinnia's & Hibiscus plants give me a rash:(

Was checking my Coneflower out for caterpillars and got a burning itchy rash on hands. Had to apply topical cream and take antihistamine. Finally realized it happens every time

I work with Coneflowers!

Another discussion about this:

https://www.houzz.com/discussions/1489753/mystery-poison-ivy-contact-dermatitis-rash-from-house-plants

This is a very old thread but plants that can cause contact dermatitis or a phototoxic reaction number in the hundreds and include many, many common landscape plantings as well as weeds. Individual sensitivity will vary widely........some are much more reactive than others.

Neighbor of mine can't pull bittersweet without getting rash.