Last year when countryside walking I've accidently got stung by a bush with big thorns. One thorn went in my thumb by the nail area. I pulled it out and disinfected the area. There was no swelling or any abnormalities, until after a couple of weeks, my nail on that thumb started to grow white. The whole nail turned white with time. After it started to grow normally, normal colour again. Then the skin on that thumb started to peal around that area where thorn was. That area is getting bigger now