A new mother is scarred for life after developing an allergic reaction to her son.

Dayle Byrom, 20, from Wakefield, UK, developed a burning rash all over her body when she was pregnant with her son Jacob, and now her legs are covered with pockmarked sores caused by constant scratching.

Doctors believe that Dayle has a rare intolerance to the hormone testosterone, which was produced by her baby as it developed in her womb. The first time mother started noticing the rash after being pregnant for 20 weeks and was soon crippled by burning pain and unbearable itching.

"The pain got worse day by day. It started when I was 20 weeks' pregnant and was at its worst at 30 weeks," she said, according to The Sun. "My skin was on fire. If I touched anything it was agony. I couldn't sit down or keep still. All I could do was itch and cry ... it felt like someone was ripping my skin off."

"I tried wearing gloves, but nothing stopped me digging at my skin. All I cared about was scratching, and everyday tasks became impossible," she said.

Dayle said that her body was telling her that she shouldn't be a mother. In fact, she was in so much discomfort that she even told her boyfriend Tom Hayward, 21, that she thought that having an abortion might be the only way to stop the pain.

"Even though I was too far into my pregnancy, I still begged Tom for an abortion. I wasn't thinking straight. I regretted ever getting pregnant in the first place," she said.

What's worse was when she pleaded with doctors for help, no one could tell her the cause of suggest treatment.

"My GP told me it was the worst case she'd ever come across. I saw ten different doctors, and no-one could tell me what caused the rash. I was prescribed all sorts of antihistamine creams but nothing made the slightest bit of difference," she said.

Later, after Jacob was born on May 6, Dayle was referred to a dermatologist at Pontefract Hospital, who suggested a rare allergy called Polymorphic Eruption of Pregnancy (PEP), a condition that usually affects only first-time mothers and flares up in the later stages of pregnancy, was to blame.

"The dermatologist said he was certain the rash was caused by an allergic reaction to testosterone which was produced while Jacob was growing inside of me. He said it was very rare to have an outbreak as bad as mine, but in the handful of similar cases, the women have gone on to have boys," she said.

Experts say that PEP affects about one in 300 pregnancies and is still not fully understood, and researchers are still debating whether the sex of the baby is a cause. Dayle's legs are now pockmarked with sores by her constant scratching.

"I was told if I didn't stop scratching immediately, I would have to be bandaged up. I've ruined my skin," she said. "The scars are very deep and, unfortunately, they're never going to heal properly.

"I'm absolutely gutted. I can't wear dresses or skirts any more. When I wore shorts in summer people stopped me in the street and asked me questions about the marks," she said. "Most women lose their confidence because of stretch marks, but mine's been ruined by the damage to my legs. When on the rare occasion I go out, I have to cover up."

Her symptoms are getting better but Dayle, who is a dog groomer, still compulsively scratches and worries that she will never be able to return to work, as shampoo and other cleaning agents now severely irritate her skin.

"Whenever I get into the bath or use baby lotion the itching comes back. I've accepted that it's something I will have to live with," she said. "After the birth I swore I would never have any more children, but I'm starting to feel a bit more confident, and we're already considering having a second child.

"I'm scared my symptoms will return when I have more kids, but I won't let it put me off. Despite my bizarre allergy, having Jacob is still the best thing I've ever done," she concluded.