Allergies are kind of bizarre because the range of reactions is so impossible to predict. The reactions can be something as small as a scratchy throat or they can actually cause a person to die. It all depends on the severity of the allergy.
The scariest thing about allergies is that you don't always know what you are sensitive to. Estelle, a 19-year-old from France, learned the hard way that allergic reactions can present in truly unexpected ways.
Le Parisien reported that shortly after dying her hair with a recognizable brand's store-bought dye, her entire face began to swell.
She had done a quick allergy test like the packet suggested, but only waited 30 minutes rather than the suggested 48 hours, and now she's regretting her impatience.
Estelle noticed that shortly after applying the dye her scalp became itchy and then it began to swell. She picked up some antihistamines hoping that it would put an end to her reaction, but it just kept getting worse.
"My forehead had doubled in volume," Estelle told the paper. "My head was like a light bulb".
She was rushed to the hospital and after being given another round of antihistamines and corticosteroids, she was sent home.
The reaction just kept getting worse. At one point her tongue had started to swell and she couldn't breathe properly so Estelle was brought to another hospital to try and get help.
Luckily for Estelle, these doctors took her situation more seriously and admitted her. Her face continued growing and they shared pictures to warn people of the serious risks of dying your own hair.
The dye contained a chemical known as PPD, which is very common in drugstore hair dyes, but Estelle's reaction was obviously more intense than average.
PPD has been banned in makeup, but it is still allowed in hair dye. It's reported that between two and three percent of the population are sensitive to the harsh chemical, but as of now the only changes to hair dyes have been to lower the acceptable limit.
While Estelle has made a full recovery, she wants other people to know the dangers of this chemical so no one else has to suffer.
"I almost died, I don't want something similar to happen to other people," she said.