Watch glass nails
Watch glass nails are a form of pathologically altered finger (seldom toe) nails. They usually do not occur alone, but in connection with drumstick fingers . Because of the thickening of the finger end links, the nails are blown in the shape of a piston. The shape of the nails differs from the normal in that the nails are larger, rounded and strongly curved outwards.
The cause is a chronic lack of oxygen in the tissue ( hypoxia ). A hypoxic-induced new formation of capillaries in the distal phalanges is assumed to be the mechanism of origin.
Watch glass nails are observed , for example, in diseases such as cystic fibrosis and in people with Eisenmenger's reaction .