Pregnant Woman's Allergy to Unborn Baby's DNA Triggers Rashes on Her Body

A mother from the United Kingdom was shocked to discover that blisters and itchy red areas on her body were caused by an allergy to her own child.

Fiona Hooker, 32, from Basingstoke, initially noticed red patches on her stomach when she was 31 weeks pregnant, which she says felt like nettle stings, the Manchester Evening News reported.

This continued to worsen during the remainder of the pregnancy, becoming "unbearable red itchy plaques" all over her skin. After the birth of her child the rashes turned to blisters that left the mother in so much pain she couldn't hold the baby, Barney.

She told the paper: "It hurt a lot to even hold my son so I wasn't really able to enjoy the newborn stage because of it. When I was in labor I didn't feel a thing, I looked horrendous but it wasn't itchy at all."

"But the postpartum bit when it exploded into blisters on my tummy, chest, arms, and legs - everywhere you would hold a baby - that was quite difficult.

Hooker was eventually diagnosed with Pemphigoid Gestationis (PG), a skin condition that usually arises during the second trimester, but can occur at any time during a pregnancy, even sometimes occurring after birth, according to the American Osteopathic College of Dermatology (AOCD).

PG is an autoimmune condition that is caused by the production of autoantibodies— antibodies that specifically react with self-antigens—proteins found in the skin. The AOCD says the condition occurs most often in people with other autoimmune diseases, but other risks factors are older age and multiple pregnancies.

PG is rare, occurring in just 1 in between 40,000 to 50,000 pregnancies according to Healthline.

The Manchester Evening News reported that doctors treating Hooker believe that it was her son's DNA that was causing her immune system to attack her own skin. She hadn't suffered from the condition while carrying her now three-year-old daughter Phoebe.

Currently, it isn't well understood why some maternal immune systems react this way, Healthline said.

Unpleasant Symptoms

Sufferers of PG usually develop red bumps that appear around the belly button which spread to other parts of the body within a few days or weeks. After two to four weeks, these bumps turn into large, red, fluid-filled blisters that can be extremely uncomfortable. Instead of blisters or bulla, some people such as Hooker, develop raised red patches called plaques.

These PG blisters often shrink or go away on their own near the end of a pregnancy, but Healthline says 75 to 80 percent of women with PG experience a flare-up around the time of delivery.

Hooker, who doesn't plan to have any more children, told the Manchester Evening News that seven months after giving birth, she still has to occasionally use steroid creams, and could suffer flare-ups for the rest of her life.

She added: "Because I'm quite recently off the steroids, every now and again I get a bit itchy and have to use a bit of steroid cream, so I think my body is still getting over it.

"A lot of people have to have immunosuppressive therapies to get off the steroids and get the condition under control so I'm quite lucky."

Hooker now wants to raise awareness of the condition, which she was previously unaware of.

Pregnant woman examined
A file photo of a woman being examined. Fiona Hooker developed rashes and blisters during her pregnancy and was shocked to discover that the cause was an allergy to her own baby. Srisakorn/GETTY