764 PASSIVE IMMUNIZATION SERUM THERAPY 



there is no diminution in the amount of membrane visible and the gen- 

 eral symptoms have not improved, the dose should be repeated. If the 

 membrane has spread and the toxemia is worse, the second dose should 

 be larger than the first. In septic cases the second dose may be given 

 in from six to ten hours after the first. If the symptoms are less urgent, 

 the interval may be extended to twelve, but should never exceed twenty- 

 four hours. 



As to the total amount of serum to be administered, continued injec- 

 tions at relatively short intervals are required until improvement has 

 taken place. So long as membrane is present and the patient is toxic 

 it is probably worth while to push the treatment unless these show a ten- 

 dency to clear away. Time must be allowed for absorption to take place, 

 and the serum should not be pushed so far as to be wasted, and, quite 

 possibly, excreted unchanged. The remedy is expensive, especially in 

 private practice, and it is obviously desirable to have due regard for 

 economy. While, as previously mentioned, physicians of such wide ex- 

 perience as McCullom, of Boston, and Woody, of Philadelphia, fre- 

 quently give 200,000 or more units in severe cases of diphtheria, others, 

 e. g., Ker, of Edinburgh, have never given more than 64,000 units to a 

 single patient, and, indeed, several of my colleagues of wide experience 

 claim that they have secured excellent results in severe infections with 

 doses that seldom exceeded 10,000 units. 



Treatment of Relapses. Occasionally, after a patient has recovered 

 from an attack of diphtheria the infection recurs after several weeks. 

 It is in such cases that the physician hesitates to administer antitoxin, 

 on account of the discomforts occasioned by serum sickness. It is true 

 that serum sickness is more likely to follow in these than in primary 

 cases, and the very profuse and itchy eruption, joint pains, and fever 

 do indeed render the patient quite uncomfortable. Since a relapse is 

 usually, although not always, comparatively mild, the serum may be 

 dispensed with if there is no involvement of the larynx and if there is 

 not much evidence of toxemia; otherwise full doses of antitoxin should 

 be given without hesitation. The subcutaneous injection of 0.5 c.c. 

 of the serum two or three hours before the main dose is given may pos- 

 sibly produce a condition of anti-anaphylaxis and ward off the more 

 dangerous symptoms. If respiratory difficulties should follow, a re- 

 injection of serum, atropin, and caffein should be administered hypo- 

 dermically. 



Antitoxin Sequelae. A certain percentage of cases will present a 

 group of symptoms that constitute the condition known as serum sick- 



