formic acid
The alkaline properties of it neutralize the acid which is what causes the pain from nettle stings
Dock leaves contain an alkaline sap that can help to neutralize the acid in stinging nettles. When rubbed on the skin after a nettle sting, dock leaves can provide relief by reducing the irritation and itching.
A stinging nettle is full of Acid and the sting from the nettle is the Acid in or on your skin. A "Dock" leaf as its called has Alkaline inside so as Science dictates Alkaline neutralises acid. Hope this answers your question for you.
Trichomes
You squeeze some liquid out of the stinging nettle and just rub it on to where it stings
Bee stings can be neutralized with bicarbonate of soda. You can make a paste with baking soda and water and apply it to the affected area to help alleviate the pain and reduce swelling.
a nettle sting is acid but a doc leaf is alkali which is why it neutralises it
Vinegar is an acid but less strong than that of a nettle so it brings the ph closer to neutral. However using something that is alkaline works better as it brings the nettle acid even closer to neutral.
He will recover OK.
Acid
You should put dock leaves on the sting. Dock leaves are alkaline and nettle stings are acid. Rubbing alkaline and acid together cause each one to water down, this is called neutralization.
Formic acid, also known as methanoic acid, but that is not the only active ingredient. Nettle sting also contains seratonin and histamine. There are also traces of oxalic acid and tartaric acid.