Meet the woman who is allergic to nearly everything. Even her own husband.

Johanna Watkins is a prisoner in her own bedroom. Her windows are sealed shut, the walls are wrapped in plastic. There’s no natural light, and few visitors. And it’s all just to keep her alive.

The 29-year-old US woman suffers from a rare immune condition called Mast Cell Activation Syndrome, which has caused her body to develop an allergic response to nearly everything in her environment.

Prolonged exposure to dust, chemicals, most foods, even the scent of other people – including her husband, Scott – could be fatal.

“I can’t get too close,” he told Fox 9. “I can’t hug her safely. I can’t hug her without hurting her.”

The scent of her husband can make Johanna ill. Image: Facebook.

The only physical contact the couple have is when Scott must whisk her to a medical appointment or the emergency room - an experience that leaves her exhausted and vulnerable.

"As soon as that door opens, I can feel it. My body goes into complete attack mode," Johanna told Fox 9. "It feels like my body is waging war on itself. My throat automatically tightens. It kind of feels like Darth Vader doing a choke hold."

Anaphylaxis is the most common reaction she experiences, but her body also battles rashes, inflammation, bone pain and loss of consciousness.

According to the station, hers is one of the most severe cases of MCAS doctors have seen. While most can be alleviated via a cocktail of medication, Johanna's has not responded to any treatment.

Three years ago, to today. Images: Facebook.

And so she has been limited to the same meals everyday for the past year, all carefully prepared by Scott using the only ingredients she can safely stomach: lamb mince, chuck steak, cucumbers and carrots.

Her days have become equally monotonous. Hours are passed reading books and Pslams, and maintaining her precious link to the outside world via email and her mobile phone.

The most cherished moments come via the weekly visits by her siblings - the only two people to whom her body doesn't react.

Scott and Johanna currently live with a family of six, who generously donated two bedrooms and their kitchen - no other food can be prepared near Johanna's and even the scent of other foods cooking has become dangerous to her.

But with the help of generous donations from the community, the couple are in the process of renovating a specially designed home, which they hope to move into next month.

“I could complain about [Johanna's MCAS] or not want it, and there are times where of course we don’t want it," said Scott, "but it’s what we have and we feel like we couldn’t have asked for a better group of people around us.”

You can contribute to Scott and Johanna's renovation fund here.