Arsphenamine Resistant Syphilis
The rapid disappearance of the cutaneous lesions of early syphilis and the Treponema pallidum from the exudate of moist lesions following the injection of an arsphenamine is one of the most spectacular achievements of modern therapy. The surface lesions almost invariably disappear within two or three weeks after treatment has begun and the darkfield examination usually becomes negative within twelve hours after the initial injection of a potent arsphenamine.
There are, however, rare cases in which the early lesions of syphilis do not heal following the injection of an arsphenamine. In these cases the darkfield examination remains positive even after several injections of arsphenamine. In still more rare cases, the manifestations of acute syphilis do not respond favorably to either the arsphenamines or the heavy metals. Because of this, Moore1 prefers to designate this type of syphilis as treatment resistant rather than arsphenamine resistant. He states that treatment resistance occurs about once in 500 cases of patients with early syphilis.
During the past two decades numerous cases of arsphenamine resistant syphilis have been reported in the European literature and, more recently, reports of similar cases by American observers have been increasing.
Certain types of late acquired visceral syphilis and of congenital syphilis respond slowly to antisyphilitic therapy and failure to attain a complete and permanent reversal of a positive serologic test is not uncommon in acute syphilis; however, these phenomena differ from those of arsphenamine resistant early syphilis. Arsphenamine or treatment resistance is a term used to designate only that. . .