I believe my son rubbed against a giant hogweed plant from the Caucasus... is there a treatment for it? Should we pop the blister? How long will it last?

It is advisable to seek medical advice if there are blisters or signs of a second-degree burn after coming into contact with giant hogweed. Blisters should be evaluated to rule out infection, as burns can easily become infected. Cold compresses, cool baths or showers, and pain medication can help provide relief. It is important to protect the affected skin from sunlight and artificial light for at least 48 hours after contact, and even longer if there is a burn. Scarring and dark spots may persist for years at the site of contact with the plant's sap. The skin may also remain sensitive to light for several months after exposure, so sun protection is crucial.