14 T. Gallard, Pathologie des Ovaires, p. 87, Paris, 1885.
ALTERATIONS IN THE FUNCTIONS OF THE SKIN.—It is a matter of common observation that the functions of the skin are profoundly influenced in many cases by the changes consequent upon the menopause. Tilt records 300 cases of more or less profuse perspiration, occurring in 500 women, due in some degree at least to the change of life. This estimate is probably exaggerated. A variety of agents influences the total amount of perspiration, as well as the relation between sensible and insensible perspiration, at all periods of life. The dryness, temperature, and amount of movement of the surrounding atmosphere, nature and quantity of food taken and liquid drank, exercise, mental condition, medicines, poisons, diseases, and the relative activity of the other excreting organs (e.g. the kidneys), are factors which deserve due consideration before attributing all increased activity of the sudoriparous glands about the forty-fifth year to the effects of the change of life. In the tables mentioned no distinction is drawn between mere coincidence and causal relation.
The perspirations due to the change of life may have prodromal signs. These symptoms are—sensations of cold, shivering, chills, sinking or faintness referred to the pit of the stomach. Usually, however, they are not attended by any premonitory phenomena. They are frequently accompanied by dilatations of the skin blood-vessels, corresponding to definite areas of distribution of the vaso-motor nerves, which are popularly known as flushes. When the perspirations following the dilatations of the skin blood-vessels are insensible, women are in the habit of terming the symptoms dry flushes. The number and duration, as well as the time of occurrence, of these sweats and flushes are various in different women. Tilt has observed them to occur as often as five or six times in an hour, and last from two to fifteen minutes. They are usually noticed during the daytime. The regions involved are, in the order of frequency, face, chest, lower portions of the trunk, upper and lower extremities. Very seldom the entire skin surface is affected. In point of intensity the heightened activity of the sudoriparous glands varies from a gentle perspiration to a drenching sweat.
The function of these perspirations and flushes cannot be regarded as definitely settled. The popular opinion is that they constitute an important outlet for the actual energy liberated by the cessation of ovulation and menstruation. Tilt, adopting the popular view, thinks that the relief obtained by increased perspiration is the most important and habitual safety-valve of the system during the change of life. There are certain a priori considerations which render this hypothesis in some degree probable.
The quantity of matter which leaves the human body by the skin, per hour, is considerable. Seguin15 has estimated it at eleven grains, while the quantity excreted by the lungs is seven grains. It is possible to isolate three factors which directly influence the secretion of sweat: (1) The skin, apart from its glandular apparatus, is a simple animal membrane, and permits a relatively small quantity of water to transude through the portions intervening between the mouths of the glands. As pointed out by Erismann,16 this function of the skin is a subordinate one. The simple transudation of water is greater through those portions of the skin abundantly supplied with glands than through those in which they are sparsely distributed. (2) Vascular dilatation accompanies, and at least aids, the secreting activity of the cutaneous surface. Bernard's experiments on the division of the cervical sympathetic and clinical observation abundantly demonstrate the operation of this etiological factor. (3) Independently of vascular supply, it is in a high degree probable that there are special nerves directly controlling the activity of the sudoriparous glands. Stimulation of the sciatic nerve causes an increase in perspiration in the toes of the dog, without any concomitant hyperæmia, as shown by the experiments of Kendal and Luchsinger.17 In a word, the skin is adequate to the regulation of aberrations in nerve-force and blood-supply and to the restoration of equilibrium. If superfluous actual energy is liberated by the cessation of the monthly ovarian stimulus and determination of blood to the uterus, it is not improbable that the perspirations and flushes of the menopause may constitute an efficient means of discharge.
15 Ann. de Chim., xc. pp. 52, 403.
16 Zeitschrift f. Biol., xi. p. 1.
17 Pflüger's Archiv, xiii., 1876, p. 212.