Is it permissible for someone who has a pilonidal cyst from which pus is exuding to lead people in prayer?

Scholars have differed regarding the impurity of pus, and the relied-upon view in the four madhhabs is that it is impure. Sheikh al-Islam Ibn Taymiyyah holds that pus and serous fluid are pure, and there is no evidence for their impurity.

If pus exits from the two private parts (front or back), it invalidates ablution. If it exits from other than the two private parts, the preponderant opinion is that it does not invalidate ablution.

A person from whom pus continuously exits from one of the two private parts should perform ablution after the entry of the prayer time and pray. Their ruling is that of one who is in a state of perpetual ritual impurity, unless the pus ceases for a period sufficient for purification and prayer; in that case, they should delay the prayer until that time.

If pus exits from other than the two private parts, the impurity must be removed before prayer as much as possible, and what is excusable is that which is difficult to remove.

The imamate (leading the prayer) of such a person is valid according to the preponderant opinion, but it is more cautious to avoid it to steer clear of the disagreement of those who dislike their imamate.