What cactus stings?

Question

my friends were cutting down a cactus/succulent and the sap sprayed on them and stung there skin, it was quite painful.

why did it do this?

and how do you treat it?

Answer 1

The sap of some succulents like the pencil cactus and the African Milk Tree is very caustic.  I burned my face and eyes with it about six months ago and the doctor flushed my eyes and face with sterile water for over an hour then used cortisone cream on my skin.  It took days for my eyes to heal.  The doctor told me I was lucky since it can cause permanent blindness.  He said the sap is highly alkaline (base), like caustic soda.