Giant hogweed (Heracleum mantegazzianum) is an invasive herb in the carrot family which was originally brought to North America from Asia and has since become established in the New England, Mid-Atlantic, and Northwest regions of the United States. Giant hogweed grows along streams and rivers and in fields, forests, yards and roadsides, and a giant hogweed plant can reach 14 feet or more in height with compound leaves up to 5 feet in width.
Giant Hogweed sap contains toxic chemicals known as Furanocoumarins. When these chemicals come into contact with the skin and are exposed to sunlight, they cause a condition called Phytophotodermatitis, a reddening of the skin often followed by severe blistering and burns. These injuries can last for several months, and even after they have subsided the affected areas of skin can remain sensitive to light for years. Furanocoumarins are also carcinogenic and teratogenic, meaning they can cause cancer and birth defects. The sap can also cause temporary (or even permanent) blindness if introduced into the eyes.
If someone comes into physical contact with Giant Hogweed, the following steps should be taken:
- Wash the affected area thoroughly with soap and COLD water as soon as possible.
- Keep the exposed area away from sunlight for 48 hours.
- If Hogweed sap gets into the eyes, rinse them with water and wear sunglasses.
- See a doctor if any sign of reaction sets in.
If a reaction occurs, the early application of topical steroids may lessen the severity of the reaction and ease the discomfort. The affected area of skin may remain sensitive to sunlight for a few years, so applying sun block and keeping the affected area shielded from the sun whenever possible are sensible precautions