Indeed, I've used it myself after touching stinging nettle, and felt immediate relief. However, I now wonder if I simply experienced a placebo effect.
There are other claims of its effectiveness as a cure-all, however I am hesitant to take an unreferenced claim of the results of a 1958 study at face value:
It apparently contains chemicals that neutralize the components responsible for the skin-irritating effects of poison oak, poison ivy and other irritants including stinging nettle, insect bites and ringworm. Folk remedies also recommend jewelweed poultices as treatment for minor injuries such as bruises, cuts, burns, sores, sprains and warts.
According to Varro Tyler in his book Herbs of Choice, a 1958 study compared jewelweed to "standard poison ivy dermatitis treatments," including corticosteroids. The researchers found that the plant was effective in treating 108 out of 115 patients, leading to complete symptom relief within two to three days.
Is there any scientific support to the claim of this plant providing relief from skin irritants, particularly those caused by poison ivy or stinging nettle (although research showing benefits against other irritants would be acceptable substitute data)? Is the 1958 study referenced above legitimate?