All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger.
According to the view that the congregational prayer in the mosque is an obligation, then the person who has acne should not miss it because it is often easy to treat it. The scholars stated that what is easy to treat is not an excuse for not attending the congregational prayer.
The author of Tuhfat Al-Muhtaaj said regarding not attending the Friday prayer because of sickness, “As for what is easy to treat, it is not a valid excuse, so he is obliged to attend.”
Besides, acne is not an infectious disease so that one would fear to affect other people with it, and it does not have a bad smell that harms people. However, if one is severely affected with it in a way that the people are harmed even by seeing him and it repels them, and he cannot treat it, then there is no doubt that the person who is affected with it is excused for not attending the congregational prayer as well as the Friday prayer.
The scholars of Fiqh stated that every repulsive disease is an excuse for the person who is affected with it not to attend the prayer in the mosque.
The footnote of As-Saawi on Ash-Sharh As-Sagheer reads, “Leprosy is like vitiligo and any repulsive disease. The point regarding what is mentioned permitting the person who is affected with leprosy to not attend the congregational prayer is if he does not find a place where he may pray separately. If he finds a place where he can perform the Friday prayer without harming the people, then he must attend, according to the agreement of the scholars, as it is possible, in this case, to combine the right of Allah and the right of the people.”
Allah knows best.