قَالَ مَالِك : وَلَا بَأْسَ أَنْ يَبُطَّ الْمُحْرِمُ خُرَاجَهُ وَيَفْقَأَ دُمَّلَهُ وَيَقْطَعَ عِرْقَهُ إِذَا احْتَاجَ إِلَى ذَلِكَ
Imam Malik, may Allah have mercy on him, said: If a person in the state of ihram lances his boil, bursts a blister, or opens a vein for bloodletting out of necessity, then there is no harm in it.