dermatologic disorders
Nail Deformities and Dystrophies
Discoloration
Cancer chemotherapy drugs (especially the taxanes) can cause melanonychia (nail plate pigmentation), which can be diffuse or may occur in transverse bands. Some drugs can cause characteristic changes in nail coloration: Quinacrine: Nails appear greenish yellow or white under ultraviolet light. Cyclophosphamide: The onychodermal bands (seal formed at the junction of the nail plate and distal nail bed at the free edge of the nail plate) become slate-gray or bluish. Arsenic: Nails may turn diffusely brown. Tetracyclines,ketoconazole, phenothiazines, sulfonamides, and phenindione: Nails may have brownish or blue discoloration. Gold therapy: Nails may be light or dark brown. Silver salts (argyria): Nails may be diffusely blue-gray. Tobacco smoking or nail polish can result in yellow or brownish discoloration of nails and fingertips. White transverse lines of the nails(Mees lines) may occur with chemotherapy, acute arsenic intoxication, malignant tumors, myocardial infarction, thallium and antimony intoxication, fluorosis, and even during etretinate therapy. These lines are not due to changes in the nail bed, but are a true leukonychia, and the nails can grow out normally if the insulting exposure has been removed. Mees lines also develop with trauma to the finger, although traumatic white lines usually do not span the entire nail. The fungusTrichophyton mentagrophytescauses a chalky white discoloration of the surface of the nail plate. . It is generally a harmless infection, usually of 1 or 2 nails, and is noteworthy for its striking blue-green color. It often occurs in patients with Onycholysis or 