Normally the plants I’ve looked at in the poisons collection have had relatively unassuming names. However, the blister bush goes for the more direct approach. This is a plant native to south Africa and grows in partially shady areas on medium to high altitudes. It’s leaves look a little like parsley but the shrub itself can grow up to 2 and a half metres tall.
As the name suggests the blister bush can cause blisters but it does it in a slightly unusual way. The surface of the plants leaves are covered with a cocktail of different chemicals. If you were to walk past it and brush these leaves you wouldn’t feel anything untoward at all. However as soon as the area that touched the leaves is exposed to any UV light thats where the problem starts. The chemicals cause a phototoxic reaction which causes blistering and severe itching. It can be extremely gruesome and from reports it can be extremely painful. Some reports have said that it can be like a bad sunburn.
In terms of treatment there are a few methods to counteract the plants defenses. Firstly being obviously not to touch it and to wear clothing that covers the skin. Secondly is that if you have touched the plant to wash the area immediately, cover it in sun tan lotion and then cover the area to prevent the phototoxic reaction. Thirdly, if the blisters have developed to wash them regularly and to keep covered. Once the itching and weeping of the blisters subsides you can uncover them to let them heal.
Either way I’d stay well away from this rather unassuming plant!