Is it acceptable to refuse someone admittance into a church if they have a very noticeable birthmark?

I know of no Christian church that would refuse someone admittance into a church based on a naturally occurring birthmark unless it was located on an area of the body that should not be publicly uncovered. As a pastor, we have an open door policy that anyone is welcomed into our services regardless of their natural appearance or the way they are dressed. The only reason I can think of to refuse anyone mere "admittance" into a church would be if they had previously disrupted services out of malice or they had voiced their desire to injure or harm someone. I am uming by admittance that you mean "just attending the church service" and not becoming a member which would concern spiritual and theological matters. Man looks on the outward appearance but God looks at the heart.