Page 183 - Concise Pathology for Exam Preparation ( PDFDrive )

168 SECTION I General Pathology

2. Secondary stage
• Secondary stage is heralded by appearance of a rash in the skin and mucous mem-
branes, seen as rough, reddish-brown spots, most prominent on palms of hands and
soles.
• The rash may be accompanied by fever, sore throat, lymph node enlargement, patchy
hair loss, headache, muscle aches and fatigue.
• Moist areas of the skin, eg, anogenital region, axillae and inner thighs may develop
broad-based, elevated plaques (condyloma lata).
• The signs and symptoms of secondary syphilis may resolve with or without treat-
ment. In the absence of treatment, the infection progresses to latent and tertiary
stages of the disease.
3. Latent stage
• The beginning of the latent (hidden) stage of syphilis coincides with the disappear-
ance of the symptoms of the primary and secondary stages.
• The latent stage can last for years and during this time the infected person continues
to harbour syphilis even though there are no active signs or symptoms.
4. Tertiary stage
• About 15% of untreated patients go into late tertiary stage of syphilis.
• This can happen even 10–20 years after the infection is first acquired and may evolve
into neurosyphilis (meningovascular, tabes dorsalis, general paresis), aortitis (aneu-
rysms, aortic regurgitation), gumma formation (hepar lobatum, involvement of skin,
bone, etc.) and others.
• Clinical manifestations include muscle in-coordination, paralysis, numbness, grad-
ual onset of blindness and dementia.
• Syphilis affecting pregnant women may lead to late abortion or stillbirth.
• Infantile syphilis may manifest with the rash, osteochondritis, periostitis, liver and
lung fibrosis.
• Childhood syphilis usually manifests with interstitial keratitis, Hutchinson’s teeth
and eighth nerve degeneration.
Histological hallmarks of syphilis include
• Obliterative endarteritis (which is seen in H&E sections as endothelial proliferation and
obliteration of the lumina by plump endothelial cells). Endarteritis is secondary to bind-
ing of spirochetes to endothelial cells through host fibronectin molecules, and is medi-
ated by delayed hypersensitivity reaction.
• Also seen is a mononuclear infiltrate rich in plasma cells.

Diagnostic Tests for Syphilis
These can be classified into

1. Non-treponemal antibody tests
• VDRL (Venereal Disease Research Laboratory) test
• RPR (Rapid Plasma Regain) test
These tests detect and quantify the antibody to cardiolipin (a phospholipid common
to both host tissues and T. pallidum). They become positive only 4–6 weeks after the
infection (making immunofluorescence of exudates from the chancre an important
investigation early in the course of the disease). They are used as screening tests and
for monitoring response to treatment because they become negative after therapy.
2. Treponemal antibody tests
• FTA–ABS (fluorescent treponemal antibody absorption) test
• Microhaemagglutination assay for T. pallidum antibodies
These tests measure antibodies that specifically react with T. pallidum, also become
positive 4–6 weeks after the infection, and remain positive even after successful
treatment. They are better than non-treponemal antibody tests in terms of speci-
ficity, but are not recommended as primary screening tests because they are not
cost-effective. They cannot be used to monitor therapeutic response because they
continue to be positive even after successful treatment.

mebooksfree.com