Gardener beware! I gave myself a dose of phyto photo dermatitis. The sap of certain plants causes the skin to become ultra-sensitive to sunlight a day or two after contact. In my case I got splashes of sap here and there on my hands, wrists and arms which caused spots and blotches of raw red skin with some blistering and peeling. There are gruesome pictures on doctor internet of arms that resemble severe burns cases so I got off lightly.

 What caused it? Well, I trimmed the dangling stems of the Mulberry seen above and also cut back a rampant Fig growing hedge-like along a south facing wall. Both are of the plant family Moraceae which (I now know) is noted for this phenomenon. It seems to be one of those things that some people are immune to, some are susceptible to and some -like me- suddenly become susceptible.

 I have pruned an enormous Fig tree grown by my father many times but never had a problem. So perhaps it was the Mulberry? Or both? Perhaps the sap of one or other happened to be particularly potent at this point in the season?

 Anyway I will be very careful to cover up from now on. A friend of mine reports that he had a similar flare up strimming weeds wearing short trousers. Various species in the Apiaceae family have the same issue e.g. Cow Parsley, Wild Carrot, Giant Hogweed etc.