Thousands of Oak processionary caterpillars have cropped up in gardens and parks across the Buckinghamshire town in the past few days, with locals complaining about suffering reactions after touching them.
The caterpillars, which are dark in colour and measure around 25mm in length, cause painful rashes and can pose a serious problem for those with asthma.
The caterpillars can cause a nasty rash. Credit: SWNS
The creatures are covered in long white hairs, which have a protein in them that causes irritation, and can often get caught in breezes before landing on people's skin.
Experts warn that if the caterpillars come into contact with human skin, they can cause itchy rashes, along with eye problems and sore throats.
A rash caused by the caterpillars. Credit: SWNS
In more extreme cases - especially for asthma sufferers - they can even lead to breathing difficulties.
Mum Britney Comayas, 22, said she suffered from a severe rash shortly after she visited her parents in Milton Keynes on 18 April with her two-year-old son Shane.
She believes she may have brushed past a caterpillar, saying: "I reckon my rashes are from that [the caterpillar] because as soon as I arrived in Milton Keynes last week I started getting a rash and it spread everywhere.
"It started with two red spots on my arm but by the next morning my spots were spreading and it looked like chicken pox."
Britney Comayas. Credit: SWNS
However, even after Britney had spoken to doctors and A&E staff, she was still none the wiser.
She continued: "No doctors know what it is, I've taken fexofenadine and acicclovir [antihistamines] and put calamine lotion but I still have the rash, and it's very itchy."
Other people in Milton Keynes have shared their pain on Facebook, with one writing: "I suffered an itchy sore rash after some gardening last weekend it's healing now. I thought it might be some sap from plants now maybe this is the cause"
Another woman also commented: "My husband has it down his face & arms really baldly. Had the same last year but wasn't sure what had caused it."
A rash from the caterpillars. Credit: SWNS
The caterpillars are not native to the UK, but started appearing in London in summer 2015.
A Forestry Commission spokesperson said: "We are working with local authorities and land managers to share best practice and to deliver a control programme of surveillance and treatment to tackle Oak Processionary Moth (OPM).
"The majority of the UK is a designated Protected Zone for this pest and we have recently strengthened import controls on oak trees to mitigate against further risks.
"The pest is a native of southern Europe and was first discovered in the UK in 2005.
"The OPM caterpillars, or larvae, emerge in spring and feed on oak leaves leaving the trees vulnerable to other pests and diseases."
The Forestry Commission has also asked the public to report any sightings of the caterpillar - or their nest, which looks like a white web - online.
Featured Image Credit: PA