Thus, in adults: 1/2, or 1, 3, 5, 8, and rarely 10;
In children: 1/10, 1/2, 1, 3.
Loewenstein and Kaufmann"s Scheme: Repet.i.tion of small dose, relying on exciting hypersensibility--2/10 mg.; in 3 days, 2/10 mg.; in 3 days, 2/10 mg.; in 3 days, 2/10 mg.
Some use 1/10 mg., or 3/4, or 1-1/4, in same way.
This scheme is based on hypersensibility created by repet.i.tion of same dose in tuberculous subjects. Scheme not used at present.
Some advise single dose: 3 or 5 mg., (on the ground that gradual increase of doses creates tolerance).
7. RULES TO FOLLOW IN INCREASING DOSE:
_a_ If no reaction with one dose, give a larger one next time, according to _b_.
_b_ If temperature rises less than 1 degree F, repeat same dose; otherwise increase.
_c_ Avoid large doses in cases of weakness, nervous temperament, children, etc. In a majority of cases smaller doses suffice.
8. AFTER INJECTION:
_a_ Rest in reclining chair two or more days, unless severe reaction requires absolute rest in bed.
_b_ Take temperature every 2 or 3 hours for 2 or 3 days.
9. GENERAL REACTION:
_a_ Rise of Temperature. Positive reaction, if temperature rises at least .5 C. (.9 F.), higher than previous highest temperature.
Degree of reaction according to Bandelier and Roepke: Slight reaction if temp. rises to 38 C. or 100.4 F. Moderate reaction if temp.
rises to 39 C. or 102.2 F. Severe reaction if temp. rises above 39 C. or 102.2 F.
Typical reaction temperature curve: Rapid rise, slower fall, normal temperature after 24 hours.
Rise begins, in average case, 6 to 8 hours after injection (may begin within 4 hours or be delayed for 30 hours).
Acme of rise in 9 to 12 hours.
Duration of reaction, 30 hours or longer.
Rise, acme and duration of reaction vary.
_b_ Symptoms:
May begin with rigor or chilliness, followed by feeling of warmth.
Following symptoms may be present:
Malaise, giddiness, severe headache, pain in limbs, pain in affected organ, palpitation, loss of appet.i.te, nausea, vomiting, thirst, sleeplessness, la.s.situde, etc.; in short, a general feeling of "illness."
With fall of temperature--disappearance of symptoms.
10. REACTION AT POINT OF INJECTION: Area of redness, swelling, tenderness; important as indicative of sensitiveness, pointing to probable general reaction with repet.i.tion or increase of dose.
11. FOCAL REACTION: Reaction at site of process, due to congestion around it.
Focal reaction is demonstrable by:
_a_ Change in physical signs; breath sounds, resonance, appearance of rales, etc.
_b_ Localizing symptoms, pointing to location of the tuberculous process.
Lungs--increase of cough, sputum, appearance of bacilli, pain in chest, etc.
Kidney--pain in the region of kidney, changes in urine findings, etc.
Joint--swelling, tenderness, etc.
Lupus--redness and exudation.
Focal reaction is an important feature of the subcutaneous tuberculin test; it permits localization of the disease in a certain percentage of cases.
Physical examination, sputum examination, urinalysis, etc., are very important _during the course of the reaction_.
12. CONTRAINDICATIONS:
Subcutaneous tuberculin test should not be employed in:
1. Cases with temperature above 100 F, by mouth (99.1 F, by mouth, according to Koch).
2. Cases in which the clinical history and physical signs make the diagnosis certain (presence of tubercle bacilli in the sputum render, of course, any other test unnecessary).
3. Cases of recent haemoptysis.
4. Grave conditions, as severe heart disease, nephritis, marked arteriosclerosis, etc.
5. Convalescence from acute infectious diseases, typhoid fever, pneumonia, etc.
13. INTERPRETATION OF THE POSITIVE SUBCUTANEOUS TUBERCULIN REACTION:
Occurrence of reaction, following the subcutaneous tuberculin test, signifies the _existence of infection_; it does not signify that the individual is _clinically tuberculous_. To quote E. R. Baldwin, of Saranac Lake: "The tuberculin test is of very limited value in determining tuberculous _disease_; it is of extreme value in detecting tuberculous _infection_."
The test results in positive reaction in cases with latent as well as active processes.
The decision as to the patient being clinically tuberculous (ill with tuberculosis) must rest on the consideration of the clinical history and the results of the physical examination.
It is maintained by some that the subcutaneous tuberculin reaction is _more rapid in onset_ and _more marked in degree_ in cases of _recent_ infection. On the other hand, the test is negative in a certain proportion of far advanced cases.
Occurrence, then, of a subcutaneous tuberculin reaction does not indicate necessarily sanatorium or inst.i.tutional treatment; neither does it absolutely indicate the necessity of tuberculin treatment. The decision rests on the consideration of all the clinical features of the case.