626 TRICHOMYCETES, ACTINOMYCETES, HYPHOMYCETES 
Pathogenesis.^ //?/?» a??.— The initial lesion, usually cutaneous, is 
a papule surrounded by an area of hyperemia, which soon becomes a 
pustule yielding a tenacious pus. The ulceration spreads slowly, dis- 
charging small amounts of thick, purulent material and surrounded 
by a red areola in which numerous papules are frequently detectable. 
As the lesion spreads the older portions of the lesion tend to become 
cicatrized and to heal. The progress of the disease is very slow, fre- 
quently requiring years to cover an area of a few square inches. It 
does not often spread to mucous surfaces, but occasionally metastases 
occur in the lungs. ^ According to Stober,^ involvement of bones and 
metastatic foci in the spleen, liver and kidney have been observed in 
a few cases. 
A7mnal Experirnentation.— Attempts to reproduce blastomycetic 
infections in dogs, rabbits, guinea-pigs, white rats and mice have 
been unsuccessful when artificially cultivated organisms from human 
lesions have been inoculated, although Klein^ isolated a blast omycete 
from milk, which produced gelatinous, tumor-like swellings and 
glandular enlargement when injected subcutaneously into guinea-pigs. 
Intraperitoneal injections resulted in the formation of firm nodules in 
the liver, lungs, pancreas, testes, ovaries and intestines. The nodules 
were composed chiefly of masses of the organisms. Tokishige^ and 
Tartakowsky^ have isolated organisms belonging to the Blastomycetes 
group from a cutaneous infection of horses, and Sanfelice® recovered 
a similar organism from a lymph gland of an ox which had a general- 
ized carcinoma. This organism was pathogenic for white rats, rabbits, 
guinea-pigs, sheep and cattle. 
The defensive mechanism which tends to limit the spread of the 
organism in the body is largely phagocytic, together with a prolifera- 
tion of regional connective tissue which tends to encapsulate and then 
restrict the progress of the lesion.^ 
The diagnosis of blastomycetic infections is best made by a micro- 
scopic examination of the contents of a papule or pustule teased out 
in diluted NaOH, and viewed unstained. 
SPRUE. 
Sprue is a disease of somewhat limited distribution in the tropics; 
a majority of cases have been reported as occurring in Asia and the 
islands off the Asiatic coast. It is more common in countries where 
rice is a staple article of diet, although there is no suggestion of a rela- 
1 Barter: De la Blastomycose humaine, Nancy, 1909 (very complete literature). 
2 Arch. Int. Med., 1914, 13, 509. 
' British Med. Jour., 1901, i, 1279. 
* Centralbl. f. BakterioL, 1896, 19, 105. 
6 Die afrikanische Rotz der Pferde, St. Petersburg, 1897. 
« Centralbl. f. Bakteriol., 1895, 18, 521. 
" Christensen and Hektoen: Jour. Am. Med. Assn., 1906, 47, 247. Davis: Jour. 
Infec. Dis., 1911, 8, 190. 
