CHAPTER VII 



THE RELATION OF THE SKIN TO NONSPECIFIC 

 RESISTANCE 



Skin Reactivity. The fact that the skin and its reactivity can be 

 influenced by a variety of systemic pathological changes and through 

 therapeutic procedures has been observed by physicians for many cen- 

 turies, indeed ever since counterirritation by means of blisters and 

 chemical irritants was introduced (about 1600 A. D.). "We often find 

 in cases of intense irritation of internal organs that blisters will not 

 vesicate the skin, but that as soon as the disease is modified they will 

 produce their usual effect," wrote Stokes (as quoted by Gillies) . Trans- 

 lated into our more modern procedure we find this same phenomenon 

 observed when we apply the tuberculin reaction to the skin of a patient 

 during any acute disease, or in pregnancy or in cachexia, and note that 

 the reaction, normally obtained in practically every adult, has disap- 

 peared. 



It is not needful in this connection to review more than briefly 

 recent ideas that have been advanced by a number of observers con- 

 cerning the direct reactions of the skin to various stimuli, or the change 

 of the skin activity following certain general alterations of the organ- 

 ism. It is known that the tuberculin reaction cannot be elicited 

 during acute infections, pregnancy, cachexia, serum disease, etc. 



Similar observations have been recorded for vaccines. Thus 

 Matthes and Rautenberg have recently shown that the digestion prod- 

 ucts of typhoid bacteria which were used as a vaccine have a far 

 greater local effect in the normal individual than in those ill of typhoid 

 fever. 



Hoke, working with the intracutaneous test, found that the trau- 

 matic reaction, as well as the intracutaneous tuberculin reaction, were 

 increased in leukemia as well as after thyroid feeding, while in cases 

 of cachexia, in fever, in local infection and in deeply pigmented skin 

 the reaction was diminished. 



Depression. Certain general conditions of the body, quite diverse 

 in their origin, are able to suppress the reactivity of the skin to tuber- 

 culin. These general conditions are obviously not specific; that is, 

 they need bear no relation to tuberculosis, nor do they alter the anti- 

 bodies and in this way effect the tuberculin reaction in a specific 

 manner because it has never been shown that there is any parallelism 



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