Hair and Nail Disorders Avalon Dermatology takes pride in being a leader in the diagnosis, treatment and management of hair and nail disorders. Some common hair disorders include various forms of alopecia (hair loss), seborrheic dermatitis, psoriasis, hypertrichosis (excess hair), bacterial, fungal and viral infections. Some common nail disorders include fungal and bacterial nail infections, psoriasis of the nails, splitting and brittleness of the nails, and irregularity in growth and appearance.