The selection of a homoeopathic remedy in childhood is made in the same way as in adults. The difference lies mainly in case taking and in in interpreting the symptoms against the normal pattern of behaviour at any particular age.
The history is supplied to greater or less extent by the mother or nurse, at any rate by someone other than the patient himself.
In formulating a plan of case taking it is therefore necessary to concentrate on symptoms which can readily be observed by someone other than the patient. The mother is usually by far the best person to give the history especially when the patient is an infant.
Not only is the mother a keen observer of her infant, but she can often give us an account of the family history, and a first- hand account of the period of gestation and labour.
INTRA-UTERINE ENVIRONMENTAL FACTORS.
The recent discovery that German measles in the mother can produce deformity in the foetus has focussed attention to this important and easily forgotten part of the childs life.  Over six hundred cases of deformity associated with German measles have now been published. Microcephaly, congenital heart disease, cataract, and deafness are the most common abnormalities.
The period of most danger to the foetus is in the early months of gestation. When the mother became infected during the first two months of pregnancy the chances of foetal deformity were 100 per cent. In the third month the figure dropped to 50 per cent. Viruses can readily pass through the placenta.
In the influenza epidemic of 1918 a high proportion of infected mothers aborted. It is well known that syphilis and occasionally other infections may be transmitted to the foetus causing injury or death.
The use of lead as an abortifacient can cause foetal abnormalities especially congenital heart disease and skeletal defects. The therapeutic use of X-rays and radium can cause foetal defects especially microcephaly.
Dennis Browne has demonstrated how intrauterine pressure can cause talipes and other deformities.
If there were any doubt that the foetus can be adversely affected by its environment in utero there are instances recorded of deformity of one of similar twins. .
Dr. Landtman of University College Hospital sums up as follows:.
“Various observations have shown that environmental principles play an important part in the aetiology of congenital malformations. Foetal abnormalities result but not of any characteristic type in relation to the various causes. The most important factor appears to be the stage at which foetal development is disturbed. Due to lack of teratogenetic characteristics, malformations caused by environmental agents may simulate abnormalities of genetic origin”.
Drugs taken by the mother can undoubtedly affect the foetus in some cases. Practically all textbooks on obstetrics condemn the use of alcohol during and immediately after pregnancy suggesting it as a possible cause of sterility, abortions, still-births and a high foetal mortality..
There is experimental evidence that alcohol tends to concentrate in the reproductive organs, and it is freely diffusible through the placenta. Carpenter has shown that in hens with immature eggs that were exposed to the fumes of alcohol for periods of two to twenty-nine hours the concentration of alcohol in the egg was often equal to or greater than the concentration in the blood stream.
The evidence about smoking during pregnancy is contradictory. There is, however, some evidence strongly suggestive that smoking may affect the foetus. The effect of nicotine in breast milk will be referred to later.
The placenta is also permeable to chloroform, ether, morphia, hyoscine, atropine, physostigmine, pilocarpine, arsphenamine, the barbiturates, sulphonamides; penicillin and various salts of sodium, potassium, copper and bismuth.
Marked emotional disturbance may affect the unborn child, and no homoeopathic history is complete without a record of any such episodes.
THE EFFECTS OF LABOUR.
In the process of birth the infant is exposed to trauma of varying degree, to anoxia, and sometimes to anaesthetics.
These observations have been made as a reminder of environmental influences before or during birth, rather than to stress unduly the risks encountered by the foetus during gestation and labour. Occasionally some outstanding event of pregnancy or labour is of the utmost value in prescribing.
It is obvious that we should consider specially the events of pregnancy and labour in children who have never thrived. Faulty milk teeth also suggests an enquiry into pregnancy, as these teeth are formed in the second half of gestation. It is, of course, impossible to rule out hereditary influences in this connection.
THE HOME ENVIRONMENT IN RELATION TO SYMPTOMS.
Even in infancy children are acutely aware of an absorb the mental atmosphere of the home or the people around them.  The nervous child has almost inevitably been brought up in an atmosphere of fear and worry. The effects of a “broken home” where father and mother have separated, or are mentally incompatible, are highly damaging. It has been noticed in child guidance clinics that the “broken home” is a frequent cause of juvenile delinquency. One of the basic needs of childhood is a sense of emotional security. In the “broken home” he does not feel secure. When a young child, under the age of five years, is removed from his mother for a period of six months or longer there is statistical evidence to show that this child has a greater tendency to develop into a juvenile delinquent than average. .