Question Summary
Must I repeat my ghusl if, after performing the ghusl, dead skin falls off and I did not repeat the washing?
Answer
In the Name of Allah, the Most Merciful and Compassionate
Once a complete ghusl has been performed, you are in a state of purity. Suppose dried skin falls off thereafter, regardless of where you do not need to re-wash that spot nor redo the ghusl. It is, however, recommended to re-wash that spot.
[Tahtawi/Shurunbulali, Hashiyat Maraqi al-Falah]
Once one removes the state of ritual impurity through the ghusl, that same ritual impurity does not return.
Hope this helps
Allah knows best
[Shaykh] Yusuf Weltch
Checked and Approved by Shaykh Faraz Rabbani