English Ivy Allergy

Very pretty! But for me, it might as well be poison ivy. And no, I haven’t mistaken the two: English ivy leaves attach singly to the stem rather than clustering as three. Plus, English ivy is evergreen; its leaves do not turn color come fall. Nor yet can I mistake poison ivy for virginia creeper, whose leaves cluster in groups of five as well as three. Poison ivy is distinct for the central leave in every cluster of three standing slightly proud of its neighbors.

It happend like this, two years in a row. For my ham radio hobby, I maintain a sky loop antenna. It is suspended via rope, pulleys, and a weights between a trio of trees. All three trees sport annual regrowths of English ivy and/or virginia creeper. Surrounding each is a carpet of periwinkle. Naturally, when working around them I first scrutinize the area for any sign of poision ivy. I found none. Were I to do so, rest assured, I would first poison it right back with glycophosphate, and not return until days later.

As stated, I found none. The next day, however, still I developed an angry red rash, complete, no less, with weeping blisters. Very much like for poison ivy instead. The worst patches appeared on the backs of my hands. Oddly, not at all on the bottoms. This despite my exposure occuring while cutting the rope-thick vines, then grasping and pulling. Lesser patches appeared on my upper forehead, these marking a line just above where I’d been wearing a sweatband. I recall dust drifting down while pulling vines from the trees. Happily, glasses kept it out of my eyes. Later I was to develop yet other pacthes in places where I’d touched myself after.

Going back out to all three trees, I searched yet again for poison ivy, still finding none. Likewise along the routes I had walked too and from. My careful search was strongly motivated as this is the second year in a row when the same thing has happend.

Vastly annoyed, I began furiously querying Google. And to my dismay there did I learn but that for a certain minority, English ivy indeed might as well be the poison variety. This despite their being completely unrelated. The first is named Hedera helix, the other Toxicodendron radicans.

In short, nothing whatever alike. And as stated, the one quite easily told apart from the other. Nevertheless, for some of us that hardly matters. And, just possibly, you likewise?

Falcarinol

Whereas poison ivy’s allergen is an oil named ‘urushiol’ to which 85% are allergic and 15% severely so, English ivy has instead two fatty alcohols: ‘falcarinol’ and ‘didehydrofalcarinol’. To both of which an unlucky few of us are no less severely allergic. Sensitization increases with repeated exposure. Among professional gardener’s having frequent exposure, 50% become allergic in time.

Serving the plant as an anti-fungal agent, all parts are equally potent. This all year long, but with fall as the season to most avoid it.

Carrots Too?

Falcarinol is a skin irritant only. Which is fortunate as carrots, celery, and parsnips also have it. In carrots the concentrations can run as high as 1/500th by weight. Yet normal consumption has no ill effect. How very odd that in dietary terms, falcarinol is even regarded a highly beneficial antioxidant.

So do medical references found online (at NHS and elsewhere) plurally inform me. And for a fact, while not very much liking carrots, I have many times consumed them chopped into stew and shredded raw into salads. I like celery quite a lot, having handled and eaten it raw times beyond counting.

Rarely have I ever peeled carrots, and do not remember ever once getting the itchies. That said however, the angry red, blistering rash I get from handling English ivy presents everywhere except on the bottoms of my hands. The rash instead popped up at many another location. All those places I had inadvertently touched later: everywhere my hands brushed while undressing to shower. How very grateful I am for apparently not having rubbed my eyes prior to washing up!

Treatment

Preventive washes designed to break down poison ivy’s urushiol oil are useless against the falcarinol in English ivy. Nor does there exist a comparative neutralizing agent for falcarinol. Which leaves only washing to remove the oils mechanically. A thread on Reddit recommends to scrub gently twice with Dawn dishwashing liquid. The sooner the better, of course.

Steroids help by moderating the allergic response. With hydrocortisone cream being the only such available OTC. Topical benedryl helps relieve the itch, but does nothing for the rash itself. Oral antihistimines likewise.

Heat is to be avoided, as it intensifies symptoms. So cool showers are recommended.