On account of the frequency with which the hands are exposed to mechanical, thermal, and more especially to chemical irritation, they are extremely common sites for eczema. The list of substances responsible for the production of eczema is exceedingly long and includes almost all the acids, alkalies, salts, dies, volatile oils, etc., employed in the various trades. Both hands are nearly always involved, though the dominant hand is often the more severely affected.
The lesions usually appear first upon the wrists or fingers and later involve the palms. Owing to the thickness of the epidermis on the front of the hand, the vesicles, when they are present, often persist for a long time with the appearance of little tapioca grains embedded in the skin. From some of them the fluid may be absorbed, making the heads scale over and dissipate; others rupture spontaneously or as the result of scratching, and leave the skin more or less ragged and worm eaten. The skin of the involved area becomes reddened, thickened by infiltration, and loses its pliability so that it often cracks, in the natural creases especially; the fissures that form are usually very painful. The itching is sometimes intense.