Syphilis.

Syphilis is the result of an infection by Trepomena Pallidum, a spirochaete. The organism is usually sensitive to Penicillin and its late manifestations are now rare. The radiologically visible complications are related to local bone reactions and bone destruction (gumma) or due to the neuropathic changes from the nervous system involvement.

In brief, the disease has three stages:

Primary Chancre; after 3-6 weeks, painless thick ulcer with regional lymphadenopathy

Secondary Syphilis; after 3 months, rash(typically on palms), pyrexia, eye inflammation.

Tertiary Syphilis, after 3-25 years;

Gumma, solid lesions with central necrosis found in any organ

Infiltrating inflammation; in the aorta it causes aneurysm and aortic incompetence and in the Central nervous system it causes, meningitis, dementia, and sensory disturbance. Bone involvement may produce a periostitis.

Radiologically one may see the results of either congenital or acquired infection. The congenital infection has some similarity with other congenital bone infections, like cytomegalovirus and measles in that the mataphyses are distorted and show patterns of lysis or bone reaction. Late changes are gummata, osteitis and Neuropathic change, the intellect is impaired and long sensory tracts may be affected, tabes dorsalis. The lower limbs are more frequently affected, when the spinal tracts are involved. The loss of pain sensation typically affects the periphery with loss of the ends of digits, acro-osteolysis. Gross destructive joint change with no osteoporosis or pain are typical, Charcot joints. The metaphyses in the young also are the major sites for visible neuropathic change, being the weakest part of the bone. Cardiomyopathies are visible on the chest X-ray with a calcific dilated aorta and aortic valve incompetance with weakening and dilatation of the valve ring.

The disease is usually acquired by sexual contact. The rare late cases that are seen would usually be an unhappy coincidence of an internal site of the chancre, lack of knowledge of a primary chancre in any new partner and the absence of the rash of secondary syphilis, which does not always appear. In the pre-antibiotic days this might have been the fate of the unsuspecting wife of a former lothario.