<unk>  is an occupational disease that affects violin and viola players. It is a cutaneous condition usually characterized by redness, thickening, and inflammation on the left side of the<unk>  below the angle of the jaw where the instrument is held. Acne-like lesions and cysts may form at the site due to foreign body reactions, and infections may also occur due to poor hygiene. The primary causes of<unk>  are constant friction and local pressure. It is well known among professional orchestra musicians but is "not well recognized by dermatologists", and a red mark on the left side of the<unk>  under the jaw "functions as an identifying sign" of a violinist or violist "in public without seeing the instrument". Although the presence of<unk>  is sometimes used as an indicator of a violinist's skill, or 'battle scars' from constant practice, many violinists never develop<unk> , due to differences in skin sensitivity, playing habits, and the materials used in the construction of the instrument. An accomplished professional player could practice hard their whole life and never develop<unk> .
Fiddler's neck
Cradle cap
Golfer's elbow
Barrel chest
Maddox wing
Saber shin
Burn center
Cramp-ring