Immunity and Cutaneous Sensitization 19 



sidered that a second infection following a deep infection was an allergic 



reaction due to the previous sensitization of the skin. Lombardo could not 

 produce allergy by the injection of trichophytin. An attack of the disease 

 was necessary to cause sensitization and immunity. Saeves also found that 

 Epidermophyton inguinale and M. audouini had little power to sensitize 

 the skin. He was able to find these fungi on the skins of inoculated animals 

 10 to 15 days after inoculation. This showed that the rapid death of the 

 fungus was not the cause of its nonpathogenicity. These experiments indi- 

 cated that a carrier of nonsensitizing fungi may pass the infection to an- 

 other person without exhibiting a visible cutaneous reaction. Saeves inocu- 

 lated guinea-pigs intracardially with suspensions of fungi and produced 

 widespread cutaneous eruptions when the infecting fungus was A. quinck- 

 eanum or T. gypseum. No lesions appeared after the injection of A. schoen- 

 leini and E. inguinale. Sabouraud also found that guinea-pigs inoculated 

 with different ringworm fungi became sensitized and remained so. Ribbert 

 injected Aspergillus intravenously into rabbits. When spores of Aspergillus 

 were then injected into the anterior chamber of the eye, less reaction 

 occurred than in rabbits not previously so inoculated. According to Marten- 

 stein, the skin cells and the blood serum of a guinea-pig infected with A. 

 quinckeanum contained certain specific bodies. If these were brought into 

 contact with spores of A. quinckeanum in vitro, a toxic substance was 

 produced. When injected, this produced a local inflammatory nodule. 

 Martenstein show r ed that A. quinckeanum produced a specific antibody, 

 first present at the site of the injection and later in remote areas of skin. 

 If fungous elements were injected and came in contact with the specific 

 antibody and with the resultant toxin, an inflammatory reaction was 

 produced. 



The nature of the trichophytin test was studied by Bloch, who sensi- 

 tized himself to trichophytin by inoculation with a fungus. A piece of his 

 skin and a piece of skin from a nonsensitized person were used in a graft 

 to cover an ulcer of the leg of another subject who was not hypersen- 

 sitive to trichophytin. Subsequent trichophytin tests elicited a reaction 

 on the skin taken from Bloch but not on that from the control or on that 

 from a remote area of skin of the recipient. This revealed a sensitivity of 

 the skin cell itself as the basis for the immune reaction. 



Bloch found that the trichophytin reaction appeared seven to eight 

 days after infection with a fungus. Peck, in an experimental reproduc- 

 tion of tinea pedis with a downy type of T. gypseum, found that a reaction 

 to trichophytin could be elicited 13 days after the inoculation of the 

 organism. Amberg noted that the test may produce a positive reaction 

 long after the disease has become cured and cited a case in which sensi- 



