BACILLI SIMILAR TO THE DIPHTHERIA BACILLUS 487 
receive prophylactic doses of antitoxin: that is, from oOO to loOO units 
of antitoxin repeated after fourteen days or until all danger is over, 
provided the Schick test is faintly or markedly positive. (See Schick 
test.) Curatively, from 3000 to 15,000 units, or in severe cases 20,000 
units, or even more, are used. In severe and desperate cases the 
antitoxin should be introduced intravenously, preferably using anti- 
toxin })repare(l without preservatives for this purpose. Antitoxin must 
be used early. If it is used early the mortality is reduced more than 50 
per cent. If the serum is used within the first twenty-four hoiu's, 
the prognosis is favorable in at least 95 per cent of the cases. The 
general death-rate prior to the introduction of antitoxin was from 
25 to 33 per cent; since the use of antitoxin it varies from 3 to 14 per 
cent. 
In a certain proportion of cases of diphtheria treated with anti- 
toxin, usually from eight to fourteen days after the administration 
of antitoxin, rashes and painful joints develop, together with fever, 
angioneurotic edema, swollen lymph glands, and albuminuria. This 
is the so-called serum disease, which is usually particularly severe in 
asthmatics, in whom there occasionally develops a true bronchial 
spasm with respiratory embarrassment. In a few cases, less than 1 
in 20,000, sudden death may occur within five to fifteen minutes 
after the injection. At autopsy there is not infrequently found a per- 
sistent thymus. These are cases of status lymphaticus. This sudden 
death is not due to the antitoxin, but to the proteins in the horse serum 
in which the antitoxin is contained.^ If there is reason to suspect that 
the administration of antitoxin will result seriously, a few drops (not 
more than j cc.) should be injected, and the remainder after one-half 
hour. The first small injection indicates the susceptibility of the 
patient; if no symptoms appear the full dose may be given with 
impunity; even if symptoms do appear, the anaphylactic shock is 
aborted by the first injection and the remainder may be given at the end 
of one hour. 
BACILLI SIMILAR TO THE DIPHTHERIA BACILLUS. 
There is a group of bacteria closely related to B. diphtherise, but 
differing from it either in virulence, morphology, or both. Certain 
of these organisms exliibit the characteristic morphology, staining and 
cultural reactions of the diphtheria bacillus, but do not form toxin; 
these strains, which are occasionally found in healthy and diseased 
throats, may be tentatively regarded as non-toxin-producing variants 
of the type organism.- 
' It should be remembered in this connection that man is less susceptible than a 
guinea-pig to serum diseases, and, furthermore, it ordinarily takes about 5 cc. of horse 
serum to bring about the anaphylactic reaction in sensitized guinea-pigs. Proportion- 
ately, it should take 200 cc. to induce the same symptoms in man. 
2 Clark: Jour. Infec. Dis., 1910, 7, 335. 
