Before you go through this you must know the first thing of all three miasms that point out to them.
Psora - Functional Disturbance
Syphilis - Destruction/Ulceration of tissues
Sycosis - Overgrowth
These three points you have to remember everytime when anyone asks you.
Most important features of Syphilis Miasm is:-
Ulceration and Destruction of tissues
Impulsive
Suicidal Tendency
Self Condemnation
Bone Pains
Deformities
Silent type of personalities
These all are the very important features, if you want to clear more watch out the video