A mum has issued a warning to parents across the UK after her toddler developed a severe rash all over his face and body after making a new friend whilst playing the garden. 

Four-year-old Oliver was out playing in the garden of his family home when he decided to befriend a dark brown caterpillar.

Half an hour later, the young boy was complaining about a painful "stinging" sensation on his face and mouth - and woke up the next day with hives and rashes all over his body.

Harrow Times: Four-year-old Oliver was out playing in the garden of his family home. (SWNS)Four-year-old Oliver was out playing in the garden of his family home. (SWNS)

Mum issues warning over everyday caterpillar that caused 'stinging' sensation

Oliver's mum, Caroline Gel, is hoping to share what happened to her son to warn others of the dangers that can come with touching these seemingly innocent critters.

The 43-year-old said: "Oliver was learning about caterpillars at school as his class were reading the whole hungry caterpillar story.

"So he went outside to play last week and took a caterpillar down off a tree.

"He even made a little house for it!

"Then around half an hour later, he was complaining about a sting on his face and mouth - my husband had recently cut the grass, so I thought it might have been a grass allergy or something".

Tending Oliver's face with ice did not do the trick however, for the next morning the little explorer woke up and was covered in a rash all over his body.

Caroline said: "It was so bad particularly around his face and mouth, but it was all over his front and back too!

"We took him to the doctors and they said they were unsure of the cause but suggested it might have been hives so gave him antihistamines to help with the inflammation.

Harrow Times: Caterpillar rash caused by brown tail moth caterpillar. (SWNS)Caterpillar rash caused by brown tail moth caterpillar. (SWNS)

Caterpillar rash caused by brown tail moth caterpillar

The mother-of-three then decided to google the caterpillar Oliver was playing with - and discovered it was a brown tail moth caterpillar.

This particular species has urticating hairs that cause an irritant effect - when they are in contact with human skin, they sometimes can result in breathing difficulties, rashes and hives.

Caroline, a career coach at Oxford University, added: "Oliver is always outside and is very curious.

"Normally I would never discourage him from touching things - but these insects are not very nice ones so I want to spread the word and make sure other people don't touch these caterpillars, especially children".

She has confirmed Oliver still has rashes but they are better than they were and have gone down thanks to the antihistamine and calamine location.

Caroline added: "Oliver was very excited about caterpillars but not anymore - he's very vocal to people now telling them not to touch them."