The Prophet (ﷺ) allowed `Abdur-Rahman bin `Auf and Az-Zubair bin Al-`Awwam to wear silk.
Sahih al-Bukhari Book 56, Hadith 134
← Previous Hadith As above. Narrated Anas:

`Abdur Rahman bin `Auf and Az-Zubair complained to the Prophet, i.e. about the lice (that caused itching) so he allowed them to wear silken clothes. I saw them wearing such clothes in a holy battle.

Sahih al-Bukhari Book 56, Hadith 133 Next Hadith → (Wearing of silk) was allowed to them (i.e. `AbdurRahman and Az-Zubair) because of the itching they suffered from.

Sahih al-Bukhari Book 56, Hadith 135