Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates that the Prophet (peace and blessings of Allah be upon him) permitted Sayyiduna Abdur Rahman bin Awf (may Allah be pleased with him) and Sayyiduna Zubair (may Allah be pleased with him) to wear silk shirts because they had itching on their bodies.
Narrated from Sayyiduna Anas (may Allah be pleased with him): Sayyiduna Abdur Rahman and Zubair (may Allah be pleased with them) complained to the Prophet (peace and blessings of Allah be upon him) about lice, so the Prophet (peace and blessings of Allah be upon him) permitted them to wear silk garments.