Mixed Chancre.
The fact that a man two or three days after an exposure begins to show a sore of Chancroidal type does not mean that he is already safe from developing a syphilitic chancre besides. In fact, it is a quite common occurrence that after development of typical Chancroid, in a week or two this sore begins to change in appearance and turns gradually into a syphilitic chancre. In other words, this man has contracted a double infection of both chancres, only their appearance takes place at different times, according to the difference in the length of time of their periods of incubation. The treatment of these mixed cases is naturally of more complicated character.