Photosensitive bullous eruption: sap and sun=no fun

[xavierdoc]

In this sunny weather I though I'd post a quick reminder that some plant "saps" can cause a blistering reaction of the skin when exposed to sunlight.

i was clearing styles with a knife on a sunny day 10 days ago. Usual hedgerow stuff- hawthorn, brambles, nettles and cow parsley.

About 24-48hrs later I noticed blisters clustered around the back of my hand and forearm, all along the "leading edge" when slashing with a knife.

I forgot to photograph them at the height of their glory so they've almost cleared up now. I generally heal well but these are like coral burn and take ages (might have been quicker with betnovate.)

Poor, left-handed phone pics:

The culprit is in here somewhere (I think the cow parsley is most likely to blame)

Take care.

Xav

 

[mrcharly]

nasty!

A sickle works better for this sort of clearing - then you don't even have to touch the plants.

 

[Myosotis]

Most likely culpit is the bracken - has been known to have this sort of reaction on skin. Quite a nasty thing is bracken....

 

[Harvestman]

I'd be surprised if cow parsley caused that. It is edible.

 

[xylaria]

Wear sunblock on the bad bit of skin for the rest of the season if you think it is carrot family .

Ivy has given me blisters, some members of thr buttercup family can also produce blisters occasional.

 

[xavierdoc]

I'd be surprised if cow parsley caused that. It is edible.

I don't know that it was the cow parsley. When I showed the blisters to a dermatologist, one of the first things he asked was whether I'd been in contact with cow parsley sap. I think he mentioned a seasonal effect.

nasty!

A sickle works better for this sort of clearing - then you don't even have to touch the plants.

I don't carry a sickle when I'm out walking! I was carrying a Byrd Crossbill as the curved blade serrations make for discreet, controlled "snips" when there is only a bit of overgrowing. If I am likely to be slashing/hacking but can't use a machete (too bulky or blatant), I take the Rajah in the pic above; an excellent tool for this niche.

 

[xavierdoc]

Just did a quick search and found a paper which lists plants which can cause PhytoPhotoDermatitis or "strimmer dermatitis":

"Relatively common causes of PPD include exposure to furocoumarins (psoralens), which are natural fungicides and are also used therapeutically in the treatment of psoriasis. Exposure to the juice of Umbelliferae, Ranun- culaceae, Moraceae and Rutaceae (bergamot, orange, lemon) plant species are recognized hazards. The Umbelliferae species include celery, parsnip and carrots, as well as weeds common in the UK, including cow parsnip (Heracleum sphondylium), giant hogweed (Heracleum mantegazzianum), Bishop’s weed (Ammi majus) and cow parsley (Anthriscus sylvestris). Occupationally related reports of the condition include soldiers on exercise, farm workers, gardeners, vegetable processors/canners, bartenders and florists [5–9].
The history provided by the workers in this case study is typical of PPD, being erythema of sun-exposed areas (typically face, neck and hands) arising 24–48h after exposure with subsequent development of a vesiculo-bullous rash. The eruption is linear in distribution if the patient has ‘brushed’ against the offending plant. Long- term hyperpigmention is a recognized sequelae. Pruritis is described by some authors as a relatively unusual feature and, however, may indicate an allergic phytodermatitis. This symptom in one employee may be a feature of the relative severity of the skin rash, however he remains under surveillance for any future symptoms that may suggest the need to exclude a type IV allergic contact dermatitis."

So cow parsley is in the frame but so are many others.

For those thinking "I don't have sensitive skin, it won't happen to me", I've never had any skin problems and I'm not allergy-prone (nor were the workers in the case series above).

What I'm surprised about is that this hasn't happened to me years before.

 

[Bushwhacker]

I don't know that it was the cow parsley. When I showed the blisters to a dermatologist, one of the first things he asked was whether I'd been in contact with cow parsley sap. I think he mentioned a seasonal effect.



I don't carry a sickle when I'm out walking! I was carrying a Byrd Crossbill as the curved blade serrations make for discreet, controlled "snips" when there is only a bit of overgrowing. If I am likely to be slashing/hacking but can't use a machete (too bulky or blatant), I take the Rajah in the pic above; an excellent tool for this niche.

More likely Hogweed - similar looking.

 

[Harvestman]

Fair enough. Good research there. Thanks

 

[mrcharly]

I don't carry a sickle when I'm out walking! I was carrying a Byrd Crossbill as the curved blade serrations make for discreet, controlled "snips" when there is only a bit of overgrowing. If I am likely to be slashing/hacking but can't use a machete (too bulky or blatant), I take the Rajah in the pic above; an excellent tool for this niche.

There are 'baby' sickles. They do work well - and if you do happen to get a 'concerned' officer of the law querying your carrying a sharp object, you are more likely to be accepted if said object is a sickle and your explanation is that you are clearing greenery from styles.

 

[HillBill]

Sounds like giant hogweed to me. Also known as giant cow parsley.

Could be a recurring issue now for years.

I'd be surprised if cow parsley caused that. It is edible.