ECZEMA, a common and important inflammation of the skin originating without visible external irritation, and characterized in some stage of its evolution by a serous exudation. For an attack of eczema two conditions are necessary; a predisposition or special irritability of the skin, and a directly exciting cause. The first condition is usually inherited or depends on some underlying constitutional state. The number of such states inculpated and their diversity are expressions of our ignorance of the real causa tion, but there is an undoubted relationship between eczema and certain forms of functional neurosis, particularly asthma. Suf ferers from rheumatism and gout are also prone to eczema, though the exact relationship is much disputed. Eczema is not con tagious, though when complicated by pyogenic micro-organisms (impetigo), it is both auto-inoculable and contagious. Females (except when menstruation is becoming established, and at the menopause) are less liable to be attacked than males. In old age the sex influence is lost.
An attack of eczema is usually described as acute or chronic, but the only distinction lies in its greater or less intensity at the time of description; it has nothing to do with the length of time that the disease has lasted. It usually begins with local itching and burning and an erythematous blush, on which numerous tiny vesicles form. The vesicles grow larger, run together, and either burst or are broken by the patient's scratching, a clear fluid exud ing which stiffens linen. The discharge does not dry up at once, but continues to exude—hence the name of "weeping eczema" when this is a prominent symptom. In some cases papules pre dominate, in others, especially when the face is attacked, erythema is more marked. The general health seldom suffers appreciably, unless the itching is so bad as to make sleep impossible. The irri tation and local heat may be out of all proportion to visible changes in the skin, and in neurotic patients the nervous excite ment may be extreme. The attack may affect any part of the body, but it usually begins at one of the following sites: the bends of the elbows or knees, the groins, between the buttocks, the groove behind the ears, the scalp, the palms or the soles, and the breasts of women. According to its position the form of the eczema is somewhat modified. On the front of the legs and arms, there is uniform redness. On the scalp it is generally seborrhoeic, and in children, especially when pediculi are present, it will be come pustular. On the palms and soles it brings about thickening of the epidermis and the formation of cracks.
Treatment is unsatisfactory. Some cases are benefited by X-rays, others by alkaline bicarbonates or calomel, but the condi tion seems to wax and wane, or even disappear in an arbitrary way and the last treatment employed is given the credit. The only safe statements are (a) that the inflamed area should be protected from air and irritation and (b) that highly seasoned foods should be avoided.