A 27-year-old British girl was diagnosed with a rare disease.
A woman named Natasha Coates has an allergic reaction when she feels strong emotions.
This includes laughter, excitement, crying.
A patient who suffered from the syndrome of hyperactivity of the dark spots once recalled the moment when he was about to die of laughter:
"I have been allergic to strong emotions since childhood. Chemical reaction starts in my body during laughter, crying, stress. I almost died laughing once. I laughed and laughed, within 5 minutes Quincke's edema started in my body, my tongue and throat were swollen. I almost died. They gave me an injection and called an ambulance. There is no cure for this syndrome."