A MUM wants parents to be aware of a plant that blistered her son’s skin.

Kirsty Hayton was shocked to see her son covered in 'red, raised marks, like welts' and 'blisters' after playing in a park.

Harry was playing in the river at Levens Park and having fun with his friends when spots started to appear.

Harry had run through a bush of giant hogweed, a plant with toxic sap.

The sap of Giant Hogweed, which grows up to five meters tall and flowers between June and July, can cause burns.

Giant Hogweed contains furocoumarin, which makes skin extremely sensitive to sunlight (phytophotodermatitis). If the sap gets onto your skin and is then exposed to the sun, you can blister badly.

Harry’s friends have only experienced small spots and blisters 'nothing like Harry's', said his mum.

Harry visited A&E to have his blisters looked at and dressed. He also has a prescription that will help with the swelling.

Kirsty said: “I knew that it was harmful for dogs but didn't realise the impact for people.

“He has come out in blisters all over his body. It started as red raised marks, like welts, but they have all slowly turned into blisters. Some are huge. He's got over 50 blisters on his arms, legs, face and stomach.

“Please keep your kids away from it and please don't pick them as there have been people putting pictures of them in vases with flowers.”

Giant hogweed is not native to the UK. It originates from Asia and was first introduced during the 19th century.

The plant is now classed as an invasive species and can be found throughout the country, it is usually found along riverbanks where its seeds are transported by water.

The Woodland Trust said it 'looks like an enormous cow parsley plant' and forms a rosette of jagged, lobed leaves in the first year before sending up a flower spike in the second year and then setting seed.

They advise the best way to avoid injury is to avoid contact with the plant but if you do get giant hogweed sap on your skin, wash the area thoroughly and immediately. Seek medical advice and do not expose the area to sunlight for a few days.