190 An Introduction to Medical Mycology 



raw fruits or vegetables. Sporotrichum schencki is pathogenic for the higher 

 animals such as horses or mules, and some of the lower animals also may 

 acquire lesions of sporotrichosis, the rat being particularly susceptible. In 

 isolated instances the disease has been acquired from the bite of a rat, 

 from patients with the disease and from cultures of the organism. 



In the majority of instances in the United States the disease in human 

 beings is probably due to contact with infected vegetation at a site of 

 local injury. The investigations of Dangerfield and Gear and of du Toit 

 have focused attention on another means of dissemination of the disease. 

 Dangerfield and Gear were certain that the infection in workers in gold 

 mines in South Africa was contracted underground, but attempts to culture 

 the fungus from rock, timber and underground water were unsuccessful. 

 Rats caught in the mine were likewise not infected. Du Toit was more 

 successful and isolated a Sporotrichum from dust floating about in the 

 air and from timber, on which it was growing profusely. He was not 

 certain that this fungus was the agent causing sporotrichosis since it was 

 less virulent when rats were inoculated and the disease could not be pro- 

 duced when the fungus was injected into human volunteers. 



(c) Clinical characteristics.— There are a number of clinical types 

 of the disease. These may be summarized as follows. 



(1) Localized lymphangitic type.— Most of the reported cases in South 

 Africa and in the United States are of this variety, in which a primary 

 lesion, or chancre, appears on an exposed part of the body. The usual site 

 is a finger or hand. In two recent cases, one of which was presented by John 

 C. Graham, the initial lesion was on the face. The primary lesion is indu- 

 rated; softening and abscess formation may take place; an indolent ulcer 

 may develop, or the lesion may vegetate. Rarely the disease remains local- 

 ized to this single lesion. Usually after a week or more a painless ascending 

 inflammation develops in the regional lymphatics, along the course of which 

 secondary nodules form and undergo changes similar to those noted in the 

 chancre. Enlargement of regional lymph nodes is uncommon (an important 

 diagnostic point in the clinical differentiation from tularemia, in which en- 

 largement of lymph nodes is a constant finding). Systemic symptoms and 

 generalized involvement are uncommon. There is little if any tendency 

 to spontaneous recovery. Scarring of varying degrees of severity remains 

 after involution of the lesions. 



(2) Disseminated subcutaneous type— In this variety, commonly ob- 

 served in France, small hard painless subcutaneous nodules of varying 

 number appear in scattered locations over the body. Within three to six 

 weeks the skin becomes involved; the central part of the nodule softens and 

 forms an abscess which may discharge if traumatized, becoming a cup- 



