Europe lagged behind the United States in the exclusive use of penicillin, with reservations lingering there which, as we will see, were not altogether unjustified. In the Soviet Union arsphenamines and bismuth were still being used as adjuncts to penicillin treatment, at least until recently. In 1968 a German report mentioned that fever therapy was still being used with penicillin in some cases of syphilitic paralysis. But by 1962 penicillin was being used alone in many other countries as well as in the United States for all stages of syphilis. Results have been nearly completely successful, with important exceptions to be noted.

Treatment of syphilis is not entirely free from problems and difficulties, but no serious infectious disease can be treated more simply or with more complete success.

The first problem is allergy to penicillin, which has increased somewhat with increasing use of the drug; but serious allergic reactions have never been common. Allergy tends to develop in persons in whom a drug has been used before and is accordingly more common in wealthier than in poorer patients, and more common with multiple injections than with single ones. It is almost unknown in treatment of treponematosis among Africans and others not previously exposed to penicillin. Where a history of allergy to penicillin exists, other antibiotics can be used effectively.

R. R. Willcox published some interesting statistics in 1964 on the prevalence of allergy to penicillin, based on experiences in England and Wales during the year 1960. With a single injection allergy appeared in less than 1 per cent of 74,000 cases treated for venereal disease, but the figure rose to 10.2 per cent for multiple injections. Fatal reactions known as anaphylaxis occurred at the rate of one in 78,002 patients treated. Willcox remarks that this rate, applied to cases of syphilis and gonorrhea reported in the United States in 1952 1961, would give an expected total of 47 deaths in ten years, which is approximately one fifth the mortality from playing" American football" in an equivalent period. He goes on to make the following comparison of penicillin deaths in VD clinics in England and Wales with deaths from other causes, all in 1960: