I would be pleased to answer your question .
It would be very important to rule out Alopecia Areata
. This condition is seen with loss of hair over specific areas over the upper lip
beard , or scalp
most commonly .
In case you have seen the above occurrence with a sudden phenomenon It could be due to Alopecia areata .
You will need to take intralesional corticosteroid injection for the same for a faster re growth .
Thanks and Take care