From him, from Ishaq, by Abdurrahman ibn Hammad, by Ibrahim ibn Abd al-Hamid, by Abu al-Hasan عليه السلام:
Imam al-Kadhim عليه السلام said “One who has marks on his face, should not lead the people in prayer.” (meaning referring to leprosy or vitiligo)
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 3, p. 311