) A fingertip is from the very end of the finger to the first crease in the finger. One FTU is enough to treat an area of skin twice the size of the flat of an adult's hand with the fingers together (ie a 'handprint'). Şiddetli Alerjiler: Anafilaktik şok gibi https://case.edu/cgi-bin/newsline.pl?URL=https://tr.wikipedia.org/wiki/Vitamin