(Idrosis; Sudatoria; Polydrosis; Hydrosis; Excessive sweating)
Definition. A functional disorder of the sweat-glands in which the excretion is excessive.
Symptoms. Natural or artificial heat, physical exercise, liberal ingestion of fluids, anxiety and other kindred emotions are natural promoters of active perspiration but in the absence of these stimuli, all excessive sweating is due to disease. Hyperidrosis may be general or local, slight or severe, of short duration or persistent. With the symptomatic or general varieties of excessive sweating such as occur in acute rheumatism, intermittent fever, phthisis and other wasting diseases, the dermatologist is not concerned. The local forms most often seen occur in the axillary and genital regions or on the palms of the hands and soles of the feet. These forms are usually symmetrical and on the warmly covered parts are apt to be associated with offensive odor (bromidrosis) and, sometimes, with erythema, intertrigo, folliculitis, carbunculosis or eczema. On the palms and soles the disorder is most common in young people who suffer from diathetic affections, such as anemia. In aggravated cases there is more or less maceration of the epidermis which may become shrivelled or flake off, leaving the parts tender to pressure. Hypertrophy of the outer layers of the epidermis of the palms, known as tylosis, is often preceded by or attended with excessive sweating of these surfaces. One-sided sweating, affecting the whole side, is rare. However, the most pronounced case that I ever saw was of this type. Less rarely, one limb or one-half of the head is the seat of the disorder.
Etiology and Pathology. Whatever the underlying causes may be, there is no doubt that deranged innervation is the medium through which local hyperidrosis is produced, whether in the nature of stimulation of the cerebrospinal system, paralysis of the sympathetic, or peripheral change. The source may be in the cerebral center, as has been observed in gumma and abscess of the brain; in the medulla, as noted in cases of excessive sweating, where tumors have been found at the post-mortem; in the cord, from lesions with aggravated reflexes; from injury to peripheral nerves, as reported by Weir Mitchell; from growths of any kind which interfere with the sympathetic. In women, hysteria and disturbances of menstruation may cause excessive local sweating. In the second stage of migraine there often is free sweating. Rare instances of congenital and hereditary cases of moderate symmetrical hyperidrosis of the palms and soles have been reported.
The disorder is purely functional as Robinson showed by failing to find any abnormal condition in the glands or epithelium of the palm. The physiological experiments of Claude Bernard demonstrating that paralysis of the sympathetic produced hyperidrosis, and of Brown-Sequard, that stimulation of the sensory fibers gave like results, emphasize the close relationship of the nervous system to the sweat function and its pathological increase.
Prognosis and Treatment. The former varies with the cause and the degree in which it is removable; the latter is directed toward the underlying causal factors so that, if local circulatory defects exist, physiological and mechanical means are employed to restore the normal condition, such as friction, exercise, cold baths and the high-frequency currents. The application of very hot water to the parts once or twice daily, a formation solution (1:100) or a strong solution of pinus canadensis extract, followed by a dusting powder of starch nd boric, acid in equal parts, may be used. If tenderness exists, a simple cerate may be used in place of the dusting powder or stearate of zinc powder or salicylic acid, 1 part to 6 of talcum, may be used with advantage. When only the feet are involved, potassium permanganate, 1 per cent. solution, will be found beneficial. Unna has recommended belladonna, 1/2 ounce in 3 ounces of eau de cologne, for sweating of the hands. A number of ointments are valuable in this condition such as 20 per cent. sulphur; Hebra’s diachylon; or tannic acid ointment composed of 1 to 2 drams to an ounce of simple cerate. The X-rays are probably the most convenient and in many cases the most permanent method of treatment. The full dose should be applied from three to six times, about every four weeks, until the sweat-glands are destroyed.
Most local treatment is, however, palliative so we must look to physiological means to remedy the corresponding errors and to pathogenetic treatment to effect a cure. Usually there are plenty of indications for a prescription from the totality of symptoms. See indications for Agaricus, Aurum mur., Antim crud., Baryta carb., Cocculus, Conium, Fluoric acid, Graphites, Hepar, Hypericum, Jaborandi, Nat. sul., N. mur., Nit. acid, Pet., Pulsatilla, Rhododendron, Sepia, Silicea, Sul. and Thuja.