What Could This Growing Bald Spot in My Facial Hair Be?

About 3 months ago I found one little spot on my chin which was bald. I asked my dermatologist about it and he told me that hair will grow there by 2 to 3 months. But the spot is now increasing its area and it looks very odd. Also I don’t have any sign of fungal/bacterial growth in that area. Can you give me some idea of what it could be? Disease? Allergy?

Without seeing you, it would be a complete guess. Alopecia areata is a possibility if there is no fungal infection present, such as ring worm. If your dermatologist was dismissive, you can try seeing another dermatologist.