The Messenger of Allah ﷺ gave license to 'Abd al-Rahman b. 'Awf and al-Zubair b. al-'Awwam to wear silk shirts during a journey because of an itch which they had.  

رَخَّصَ رَسُولُ اللَّهِ ﷺ لِعَبْدِ الرَّحْمَنِ بْنِ عَوْفٍ وَلِلزُّبَيْرِ بْنِ الْعَوَّامِ فِي قُمُصِ الْحَرِيرِ فِي السَّفَرِ مِنْ حِكَّةٍ كَانَتْ بِهِمَا