User Identity management can be done via ERC725 and ERC735.
Apart from ERC725, There are many projects being developed for identity management in Blockchain.
Some of them are:
1.Decentralized Identity Foundation:
The Decentralized Identity Foundation (DIF) was created by Microsoft, Blockstack, Sovrin, and others to establish a very simple, common framework for making claims about identities using different kinds of decentralized technologies.
Hope this helps