All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
We do not say that dead skin invalidates Wudhoo'; rather, we say that dead skin prevents water from reaching the (new) skin underneath during Wudhoo’ and thus should be removed before it, otherwise, the Wudhoo’ will be incorrect. Dead skin is the flakes that cover the living skin and thus should be removed as underlined in Fataawa 126745, 130286 and 148917.
We advise the questioner to beware of satanic whisperings about this; verily, they lead to grave evil. When in doubt about whether the skin is dead and thus prevents the purification from being incorrect, she should (disregard these doubts and) follow the basic principle which is that the skin is originally living, not dead.