NATURAL IMMUNITY: (A) PROTECTION OF THE BODY SURFACES; (B) THE RÔLE OF INFLAMMATION.
(A) Virulent organism (e. g., staphylococci and streptococci) exist normally on the skin or between the superficial horny cells, some exceptional circumstance being necessary to enable them to penetrate deeper and to cause disease (wounds). It is evident, then, that the physiologic shedding of the superficial horny cells and their continual reformation at a deeper level is a process calculated to rid the surface of the body of many micro-organisms.The question whether micro-organisms can ever penetrate the unbroken skin has been much discussed. Although experiments have shown that traumatism is not absolutely necessary, clinical experience indicates that these so-called cryptogenetic infections are not of ready occurrence. When they do occur, the infection atrium is probably one of the glandular orifices.Soluble poisons such as aconite and bacterial toxins are not absorbed through the unbroken skin.
Special Article.IMMUNITY.. JAMA. 1905;XLIV(8):625-627. doi:10.1001/jama.1905.02500350035002