A dermatologist specializes in treating disorders of the finger and toenails. When a nail is painful, changes color or texture there may be an underlying medical condition at fault. Psoriasis, fungal infections and autoimmune disorders are just a few of the causes of nail conditions. If a nail turns black or brown without trauma, you should call us right away. If you have symptoms of concern on your nails, we can treat it at Bryn Mawr Dermatology.