The French investigators Ligneres and Berger, also Lautier, have used diluted tuberculin (1:100 aqua) instead of the salve; personally I have used pure tuberculin for percutaneous reactions.
The advantage of these methods of application consists in avoiding inoculation of which some people stand in dread. In certain cases it may even he possible to obtain the reaction without the knowledge of the patient or his family and to save them all anxiety in spite of positive findings. In regard to reliability, the percutaneous reaction is but little inferior to the cutaneous method, although the reactions it produces, especially when pure tuberculin is used, are sometimes more violent than one would like to see.
Intracutaneous reactions, recommended by others (also the Auriculo reaction of Tedeschi, which has nothing to do with the present subject) have not met with much appreciation and hold the middle between the subcutaneous and cutaneous application of tuberculin.
A direct warning, however, should be sounded against the so-called ophthalmo-reaction or conjunctival reaction, introduced into the diag nosis of human beings by Calmetti and by Wolff-Eisner. The reaction is obtained by instilling a drop of diluted, glycerin-free tuberculin (1 : 100 or 1 : 200 water) into the conjunctival sac near the inner can thus. In the tuberculous it will cause a reactive conjunctivitis. The method has no advantages whatever over the cutaneous, and so many untoward manifestations have been observed in connection with it that it must be refused admittance into pediatric practice.
Other biological methods for the diagnosis of tuberculosis (agglu tination, complement fixation, serum precipitation through bacterial lipoid substances (Stoerk), serum activation through lnemolysis of cobra poison and horse blood (Calmetti) need not be discussed as being out side the scope of this handbook. Interesting though their perspec tive may be, they have not yet passed beyond the stage of laboratory experiments.
considering measures of prophylaxis we shall first speak of the general precautions which should be taken to protect all chil dren, and then of the special precautions which those should take who are predisposed to tuberculosis either by heredity or by their surroundings.
1. General Precautions: (a) increasing the powers of resistance of the body, (b) care that the child be subjected to the contagion of the tubercle bacillus as rarely and as late in life as possible.
(a) As regards increasing the powers of resistance, it would carry us too far afield to repeat. what has already been said in the general part of this work. Of prime importance in this connection is breast feeding. A child nourished at the breast has greater resistance against all infections, including infection by the tubercle bacillus. If artificial feeding he unavoidable, by all means, let it be carried out rationally, as regards quantity. Overfeeding as well as underfeeding during infancy weakens the protective agencies of the body. A mixed diet in which green vegetables have their proper share, must be begun at the proper time.
Alcohol paves the way for tuberculosis in childhood as at other periods of life. It should be absolutely excluded, forbidding even a glass of beer or medicinal wine. In order to protect the child against tuberculosis, its body should be hardened, its muscles made firm by exercise, and its lungs developed.
Antenna, which is found more often among the pampered children who idle indoors, must be treated by dietetic measures. Furthermore, great attention must be paid from early infancy to disorders of the upper respiratory organs. Any catarrh of the nose or throat should receive prompt treatment; enlarged tonsils and adenoids should be removed early.
(b) In the prevention of infection a good general rule is that "a priori every person is suspected of having tuberculosis." Strangers should not be allowed to fondle children, especially during infancy, and above all, kissing should be prohibited. Tuberculosis should be borne in mind when selecting a nurse. Her family history should be considered as well as her own physical condition, and if there is any doubt, resort should be made to the tuberculin test. The choice of the other ser vants is of equal importance. Any one suffering from an active tubercu losis should not be tolerated in the vicinity of children. Cases where a phthisical nurse has infected a child of healthy parents are by no means unheard of. Midwives ought also to be examined for tuberculosis. Later in life, children may be exposed to this infection by their teachers or fellow pupils. Institutions that farm children to private individuals should sec to it that there is no danger from this source.