At first glance, you wouldn't notice anything odd about Louise Sara's skin, but she has a dermatological condition that can take people quite by surprise. She has a condition that is called dermatographia, which essentially means "skin writing." When Louise Sara drags a pointy object like a chopstick across her skin, writing seems to appear out of nowhere in the form of raised scratch-marks. 

Louise Sara originally uploaded her own video to YouTube to illustrate what dermatographia looks like, and the YouTube channel, Science Channel, then picked up her footage and provided an explanation for the condition in their own video, below. 

Carin Bonder, a biologist featured in Science Channel's video explains that "This is quite a complicated chemical reaction that she's (Louise Sara) causing." She goes on to explain that just below the surface of the skin, there are mast cell receptors that will release histamine into the bloodstream when the skin is scratched. The release of histamine is something that most people would associate with an allergic reaction, but in the case of those with dermatographia, it's not an allergic reaction at all. In people with dermatographia, it is trauma to the skin that causes the release of histamine. 

According to the Mayo Clinic, most people with dermatographia do not seek out any kind of treatment because the condition does not cause them discomfort or harm. Louise Sara explains in her original video that her skin reactions are not painful, but simply get a bit itchy sometimes. For those who have more discomfort associated with the symptoms of dermatographia, allergy medicines like Benadryl (diphenhydramine), Allegra (fexofenadine), or Zyrtec (cetirizine) can be helpful in offering relief. To reduce severity of symptoms without medication, the Mayo Clinic suggests avoiding skin irritants such as itchy clothing, harsh soaps, and hot showers, and suggests keeping your skin regularly moisturized.  

Take a look at the video below to see just how dramatic the marks of dermatographia can be!