2. Syphilis
Cause
causative organism is Treponema pallidum
Presentation
Congenital syphilis
Acquired syphilis, by:
1. transfusion with contaminated blood
2. accidental inoculation
3. Sexual contact with an infected partner is most
important route
3. Presentation
incubation period (9–90 days)
Primary Syphilis
a primary chancre develops at the site of inoculation.
Often this is genital, but oral and anal chancres are
not uncommon.
A typical chancre is a painless, button-like ulcer of up
to 1 cm in diameter accompanied by local
lymphadenopathy.
Untreated it lasts about 6 weeks and then clears
leaving an inconspicuous scar.
4. Secondary Syphilis
The secondary stage may be reached while the chancre
is still subsiding.
Systemic symptoms of:
Generalized lymphadenopathy
Eruptions that at first are macules and inconspicuous,
and later papules and more obvious. Lesions are
distributed symmetrically and are of a coppery ham
colour. Sometimes they resemble pityriasis rosea or
guttate psoriasis. Classically, there are obvious lesions
on the palms and soles. Annular lesions are not
uncommon.
Condylomata lata are moist papules in the genital and
anal areas.
Other signs include a ‘moth-eaten’ alopecia and
mucous patches in the mouth.
5. Tertiary Syphilis
Nodules that spread peripherally and clear centrally,
leaving a serpiginous outline.
Gummas are granulomatous areas in the skin, they
quickly break down to leave punched-out ulcers that heal
poorly, leaving papery white scars.
Clinical course
Even if left untreated, most of those who contract syphilis
have no further problems after the secondary stage has
passed.
Others develop the cutaneous or systemic manifestations
of late syphilis such as gummas and dementia.
7. Differential diagnosis
The skin changes of syphilis can mimic many other skin diseases.
Always consider the following.
1. Chancre
Chancroid (multiple and painful)
herpes simplex
anal fissure
cervical erosions
2. Secondary syphilis
Eruption – measles, rubella, drug eruptions, pityriasis rosea, lichen
planus, psoriasis
Condylomas – genital warts, haemorrhoids
Oral lesions – aphthous ulcers, candidiasis
Alopecia – tinea, trichotillomania, traction alopecia
3. Late syphilis
Bromide and iodide reactions, other granulomas, erythema
induratum.
8. Investigations
Dark-field microscopy in primary and secondary stages to show up
spirochaetes in smears from chancres, oral lesions or moist areas in
a secondary eruption.
Serological tests for syphilis become positive only 5–6 weeks after
infection (usually a week or two after the appearance of the chancre).
1. The non-treponemal (rapid plasma reagin [RPR] and Venereal
Disease Research Laboratory [VDRL]) tests are 78–86%
sensitive in primary and 100% sensitive in secondary syphilis
2. False positive results confirmed with more specific treponemal
tests such as the fluorescent treponemal antibody/absorption
(FTA/ABS) and T. pallidum particle agglutination (TPPA) tests
HIV infection may cause false negative results.
Serological tests may not become negative after treatment if an
infection has been present for more than a few months and thus
cannot be relied on to differentiate between active and successfully
treated infections.
Patients with syphilis should be screened for concurrent STD,
including gonorrhoea and HIV.
9. Treatment
Penicillin is still the treatment of choice, given
parenterally for 10 days in early syphilis and 17 days
in late stage disease or in early syphilis with
neurological involvement.
Doxycycline for 14 days or azithromycin for 10
days are alternatives for those with penicillin allergy.
Patients with concomitant HIV infection need longer
treatment and higher doses.
Every effort must be made to trace and treat infected
contacts.
11. Clinical Manifestations
Genitalia.
Men:
Urethral discharge ranging from scanty and clear to
purulent and copious
Women:
Periurethral edema, urethritis.
Purulent discharge from cervix but no vaginitis.
In prepubescent females, vulvovaginitis.
Bartholin abscess.
12. Anorectum.
Proctitis with pain and purulent discharge.
Pharynx.
Pharyngitis with erythema occurs secondary to oral-
genital sexual exposure. Always coexists with genital
infection.
Neonate.
Conjunctivitis, swollen eyelid, severe hyperemia,
chemosis, profuse purulent discharge; rarely, corneal
ulcer and perforation.
Usually in absence of genital infection.
13. Differential Diagnosis
Urethritis.
C. trachomatis urethritis,
Ureaplasma urealyticum urethritis
Trichomonas vaginalis urethritis
Reiter’s syndrome.
Cervicitis.
C. trachomatis or HSV cervicitis
15. Laboratory Examinations
Gram Stain
Gram-negative diplococci intracellularly in PMN
leukocytes in exudate
Culture
Men: Urethra, rectum, oropharynx.
Women: Cervix, rectum, oropharynx
Isolation on gonococcal-selective media, i.e.,
chocolatized blood agar.
Antimicrobial susceptibility testing important due to
resistant strains.
16. Course
Most infected men seek treatment due to symptoms
early enough to prevent serious sequelae
Most infected women have no recognizable
symptoms until complications such as PID, tubal
scarring, infertility, or ectopic pregnancy occur.
17. Treatment
Localized uncomplicated gonorrhea.
Single dose intramuscular ceftriaxone 125 mg or oral
cefixime 400 mg.
Alternatives
intramuscular ceftizoxime 500 mg, or intramuscular
cefotaxime 500 mg, or intramuscular cefoxitin 2 g with
oral probenecid 1 g.
Penicillin Allergy.
intramuscular spectinomycin 2 mg.
Disseminated gonococal infection.
Intramuscular or intravenous ceftriaxone 1 g every 24
hours.
Alternatives:
intravenous cefotaxime or ceftizoxime 1 g every 8 hours
or intramuscular spectinomycin 2 g every 12 hours.
