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Secondary syphilis (lues II)

Synonyms: Lues II

By Dr. Pascal Bafteh · last updated 09/2026

Secondary syphilis (lues II): firm, sharply demarcated, painless ulcer (hard chancre) on the tip of the left index finger with a glistening red base; extragenital chancres arise at the site of entry and heal within 3–6 weeks even untreated (Photo: CDC) — CDC, „Extragenital syphilitic chancre of the left index finger (PHIL 4147)", Public Domain, via Wikimedia Commons · Public domain · Source

Secondary syphilis (lues II): round, sharply demarcated ulcer with a raised rim and smooth base on the dorsum of the tongue; oral chancre after orogenital contact (Photo: CDC/Robert E. Sumpter) — CDC/Robert E. Sumpter, „Circular primary syphilitic chancre on the tongue", Public Domain, via Wikimedia Commons · Public domain · Source

Definition & Pathogen

Pathogen: Treponema pallidum (subsp. pallidum), obligate human-pathogenic spirochete, not culturable in vitro.
Transmission: sexual (mucosal contact), vertical (transplacental → congenital syphilis), rarely transfusion/needlestick.
Incubation period: 10–90 days (Ø 21) until primary lesion.
Global incidence rising again since 2010, especially in MSM and HIV co-infection.

Clinical (Stage Course)

Primary stage (3–4 weeks): Chancre (painless, indurated) at the inoculation site (genital, oral, anal) + painless regional lymphadenopathy.
Secondary stage (6–8 weeks post-infection):
Syphilitic roseola: generalized maculopapular rash incl. palms/soles — pale salmon to pink, ill-defined macules, not raised, without scaling and typically without itch; which is exactly why patients often do not notice them and do not mention them.
Palmoplantar syphilids: round, livid-red lesions on the palms and soles. The specific marginal sign is the collarette of scale that surrounds the lesion like a collar (Biett collar). Involvement of the palms and soles is the cardinal sign of lues II — hardly any other disease produces lesions there, and that is what gives it away.
How discreet the findings can be: the same patient on the same day — a clear lesion with a collarette on the palm, only two pale macules on the sole, a few barely visible spots on the trunk. The diagnostic trap is not the striking picture but the inconspicuous one: anyone who does not deliberately search the palms and soles in a young adult with an unclear, non-itchy truncal rash will miss the diagnosis.
Condylomata lata (perianal, intertriginous, highly infectious)
Mucous patches (mucosal lesions)
Moth-eaten alopecia (alopecia areolaris, pathognomonic, occipital)
Constitutional: fever, generalized lymphadenopathy, splenomegaly
Latent stage: asymptomatic, serologically positive (early < 1 year, late > 1 year).
Tertiary stage (years to decades):
Gummas (granulomatous destruction of skin/bone/organs)
Cardiovascular syphilis: aortitis, aortic aneurysm, aortic insufficiency
Neurosyphilis (tabes dorsalis, general paresis, gummatous neurosyphilis)

Diagnostics

Confirmatory test: FTA-Abs (IgG/IgM differentiation possible).
Activity marker (non-treponemal): VDRL/RPR (quantitative) — titer correlates with disease activity.
Neurosyphilis: Lumbar puncture (cell count, protein, VDRL, TPPA index).
Syphilis serology sequence: Screening TPPA/TPHA → Confirmatory FTA-Abs → Activity marker FTA-Abs-IgM + quantitative VDRL.
TPPA positive + VDRL negative: Serologic scar or very early infection — follow-up recommended.
Direct detection (primary stage): dark-field microscopy of ulcer exudate, PCR from lesion.

Complications & Special Forms

Lues maligna: severe ulcerative-necrotic variant in HIV co-infection.
Congenital syphilis:
Early (< 2 yrs): pemphigus syphiliticus palmoplantar, coryza syphilitica, hepatosplenomegaly, osteochondritis
Late (> 2 yrs): Hutchinson triad (notched teeth, interstitial keratitis, sensorineural deafness), saddle nose, saber shin
Jarisch-Herxheimer reaction: Fever/rash/chills 2–8 h after first penicillin dose — caused by the breakdown of treponemes with release of lipoproteins and a subsequent cytokine surge. Prophylaxis: prednisolone 1 mg/kg BW p.o. or i.v. 30–60 min before the first penicillin dose, especially in neurosyphilis, ocular and cardiovascular syphilis and with a high organism load in the secondary stage; in pregnancy a pronounced reaction may trigger preterm contractions. The Jarisch-Herxheimer reaction is not a penicillin allergy — the antibiotic is continued and managed purely symptomatically (antipyretics, fluids).

Differential diagnoses

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