Priscilla Skeeter (or Reddit user pskeeter) suffers from dermagraphism (also known as skin writing)—an unusual allergic reaction that causes the 21-year-old’s skin to erupt in itchy welts whenever any sort of touch or pressure is applied.

The condition is so rare, in fact, that only around 1 percent to 5 percent of the population is affected by it.

People with this disorder can turn their skin into a living, breathing, organic Etch A Sketch. Doodling on skin with a pencil—or even fingers—provokes a rash that sort of looks like a natural tattoo.

Merely scratching or lightly stroking the skin releases histamine, which causes the reddish inflammation. The “skin drawings” usually fade away within 30 minutes.

Reddit user scumtarty, another Redditor with the allergy, shared a time-lapse video of his arm after he spelled what else but “Reddit” on it.

Scientists are unsure why people develop the allergy. Although various diseases along with diabetes, menopause, drugs, stress, or even the common cold have been shown to trigger the affliction, according to one study.

While this might seem like a novel (and even fun) disorder, it affects all aspects of a person’s life, as Skeeter explained. During an Ask Me Anything session, she discussed what it’s like to have sex, poop, and even get a tattoo when you’re allergic to touch. Check it out some of the answers from her post.

When Were You First Diagnosed?

“When I was 13, I kept getting welts constantly, and I live in California and there’s a massive bed bug problem here. I lived with my grandparents at the time and I’d always think we had bed bugs and I’d always notify them about it, they thought I was crazy and I also thought I was crazy due to the fact that I would take a hot shower and my ‘bites’ would go away immediately. “They thought I was so obsessed about the bed bugs that I formed an allergic reaction in my mind and then they finally took me to a dermatologist, who notified me I needed to have allergy tests done. after 5 years of allergy tests and my welts never going away and no cure for dermagraphism …”

What’s Your Biggest Day-to-Day Annoyance?

What’s Sex Like?

“I’m fine while having sex, but it’s after sex that’s always super annoying because I’m always very itchy. If there’s ever any contact like spanking or choking I have huge welts on myself afterwards, but it’s just itchy, never too horrible. “My current boyfriend thought he might kill me the first time we’d have sex. No [I don’t avoid kissing or holding hands], i’m super needy so even if it does make me itchy, i need it.”

Do Your Genitals Puff Up During Vaginal or Anal Sex?

“No, haha. Not the inside [of my vagina]. Never tried my butt, but the outside of my vagina kinda will, not as bad as the rest of my body though.”

What Happens If Your Breasts Are Grabbed?

Has This Affected Your Sex Life?

“My boyfriend thinks it’s cool now and like if he spanks me or anything halfway though he’ll be like ‘LOOK AT THE WELT!!!’ but no it doesn’t effect my seclude with him, but it might possibly with other people, like I can see how some people wouldn’t be into possibly killing someone you’re having sex with.”

What’s It Like to Go “No. 2” and/or Shower?

What Does a Reaction Feel Like?

Do Your Hands Swell If You Hold Something Tight?

What’s It Like When You Cut Yourself?

How Sensitive Are You to Touch?

“I have a huge rose on my knee cap, it was awesome when I first got it, then I got it colored and my skin rejected most of the colored ink. So now all of my other tattoos are just black and grey. here are some photos for you!”

How Long Does the “Skin Writing” Last?

Do Your Friends Ask to Draw Things on You?

Check out Priscilla Skeeter’s full Ask Me Anything post for more about how she lives with dermagraphism.