194 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Since it is the aberrations of sweating which are my main theme, let me concentrate for a moment on the findings pertaining to these and their roles in producing "dry skin." Whenever the sweat delivery to the skin's •urface is absent or materially impaired (e.g., in the sweat retention syn- drome), lack of sufficient surface lipids and dryness and scaliness are likely to result. Moreover, whenever the environmental climate or other conditions are such as to favor the delivery and persistence of increased amounts of sweat on the skin surface, there is a tendency f'or excessively dry and scaly skin conditions to improve. To cite but a few of the many clinical and experimental observations supporting these statements: (A) Patients with ichthyosis or other dry scaly eruptions and deficient grease on their skin's surface almost uniformly improve when in environ- ments with relatively constant high temperatures and especially with high humidities. (B) Many dry scaly eruptions, including "seborrhea sicca" or dry scaly dandruff, improve seasonally with hotter and more humid weather, e.g., in the summer in and around New York City. (C) General states of health which are associated with decreased delivery of sweat (such as hypothyroidism) will often have "dry skin," "dry hair" and "dry nails" and will often improve when the basal metab- olism is raised, more heat is produced and more sweat is consequently required and supplied. (D) When sweating is locally reduced or abolished by such procedures as sympathectomy, sympatholytic drugs, local x-rays, etc., dryness of the skin surface often becomes apparent conversely, when sweating is con- sistently increased by various measures (e.g., by thermal stimulation or by pilocarpine) softening of the skin surface is a usual resultant. (E) The common dermatologic difficulties called "chapping, .... dish- pan hands" and by a variety of other picturesque names, are much more likely to occur during cold weather and especially cold dry weather when the amount of sweat delivered and remaining on the skin's surface is at its lowest. Indeed in the climate of New York City true chapping of the hands is practically confined to the winter season, does not occur and cannot even be produced experimentally during the humid heat of sum- mer. (Unpublished experiments by Ehrenreich and Sulzberger.) It seems to us that the simplest and most reasonable explanation of all these findings is that the increased delivery and persistence of sweat at the skin's surface serves to more efficiently emulsify the sebum and other lipids and enhance their delivery and flow. In this way there is supplied and maintained, on the surface and in the subsurface intracorneal recep-

CLINICAL DISTURBANCES IN SWEATING 195 tacle, a more adequate lipid-and-water emulsion. From this emulsion come both the greasy lubricants and the aqueous components acting as hydratots and softeners of keratin* and hence the "softening" of the skin surface. Whenever this natural softening and lubricating process can be initiated or supported by correctly designed and consistently executed therapeutic measures, it appears to be more effective and somewhat more durable than the evanescent palliative effects which can be achieved with even the very best "softening lotions," or "emollient creams" which are available today. I am fully aware, ladies and gentlemen, that in this presentation I have raised many questions and problems whose theoretical answers and practi- cal solutions I have been wholly unable to supply. I think, however, that you will agree that the clear recognition of a problem is usually a first step and often the essential prelude to its adequate study and eventual solution. I hope that some of the things I have said today may serve as such useful preludes to fruitful studies of certain very common and fundamental cosmetic defects of the human skin, hair and nails, for example, their excessive dryness and brittleness, oiliness and greasiness, thickness and "blotchiness." With well-planned studies and the combined resources, skills, experience and techniques of the dermatologist, the cosmetic chemist and other scientists working in concert on these basic problems, who can doubt that the next years will bring forth signal advances in the preven- tion and relief of both the cosmetic defects and the more serious derma- roses associated with disturbances in the delivery of sweat. REFERENCES (1) Sulzberger, M. B., Herrmann, F., and Zak, F. G., "Studies of Sweating. I. Prelim- inary Report with Particular Emphasis on a Sweat Retention Syndrome," •7. Investiga- tive DermatoL, 9, 221 (1947). (2) Sulzberger, M. B., and Zimmerman, H. M., "Studies on Prickly Heat. II. Experi- mental and Histologic Findings," Ibid., 7, 61 (1946). (3) Sulzberger, M. B., Zimmerman, H. M., and Emerson, K., Jr., "Tropical Anidrotic Asthenia (Thermogenic Anidrosis) and Its Relationship to Prickly Heat," Ibid., 7, 153 (1946). (4) Sulzberger, M. B., and Herrmann, F., "The Clinical Significance of Disturbances in the Delivery of Sweat," Springfield, Illinois, Charles C Thomas (1954). (5) Shelley, W. B., "Experimental Miliaria in Man. V. The Effect of Poral Closure on the Secretory Function of the Eccrine Sweat Gland," 7. Investigattve DermatoL, 22, 267 (1954). * It appears that the sufficiently prolonged systemic administration of sufficiently large amounts of vitamin A is of some value in contributing to the "softness" of the horny layer and thus in alleviating certain forms of"dry skin", "dry hair" and brittle nails. Perhaps a similar mechanism is involved when estrogens and other hormones appear to have a softening effect.