Abstract: Objective: To analyze the clinical profile, laboratory characteristics and prognostic factors in patients with secondary syphilis. Methods: A retrospective study was performed on 126 patients diagnosed with secondary syphilis who received regular follow-up at People's Hospital of Ningxia between January 2018 and January 2023. Descriptive analysis was conducted on the data of clinical manifestations, laboratory test results, and treatment responses. Results: The mean age of onset was 28.84 years (16-61 years), with a male-to-female ratio of 1.74∶1. Among the 126 patients, 1 case had neurological involvement of secondary syphilis, 4 cases were HIV-positive, 12 cases had condyloma acuminatum, and 3 cases had both condyloma acuminatum and HIV infection. Eighty-two cases presented with dark purplish-red macules or patches on the trunk and extremities, among which 5 cases were complicated with chancres; 30 cases had copper-red patches with collarette-like desquamation on the palms and soles; 8 cases suffered from moth-eaten alopecia; and 6 cases presented with perianal condylomata lata. Laboratory findings showed that all patients were positive for TPHA and TRUST. The TRUST titers were distributed as follows: 1∶8 in 6 cases, 1∶16 in 42 cases, 1∶32 in 46 cases, 1∶64 in 18 cases, 1∶128 in 10 cases, and 1∶256 in 4 cases. For treatment, 119 patients received intramuscular injection of benzathine penicillin, 5 patients took doxycycline orally, and 2 patients received intravenous infusion of ceftriaxone sodium. Among the 32 patients with baseline TRUST titer ≥1∶64, 24 cases received prednisolone pretreatment with only 1 case having fever; 8 cases underwent direct benzathine penicillin anti-syphilis treatment, all of whom had fever. Three months after treatment, the TRUST titer of all patients decreased by more than 4-fold; at 6 months, 120 patients had TRUST titer reduced to below 1∶8; after 2 years, 105 patients achieved TRUST seroconversion, and 21 patients (16.67%) developed serofast state. The serofast rate in the HIV-positive group (4/7, 57.14%) was significantly higher than that in the non-HIV group (17/119, 14.29%, P=0.002). Additionally, the serofast rate in patients with baseline TRUST titer ≥1∶64 (12/32, 37.50%) was significantly higher than that in patients with TRUST titer ≤1∶32 (9/94, 9.57%). Conclusion: The most common cutaneous manifestation of secondary syphilis is dark purple macules or patches on the trunk and extremities. Patients with TRUST titer ≥1∶64 or concurrent HIV infection are more susceptible to developing serofast state. For patients with TRUST titer ≥1∶64, combined oral prednisolone pretreatment can effectively reduce the risk of Jarisch-Herxheimer reaction.

Key words: secondary syphilis, neurological damage, HIV, condyloma acuminatum, chancre, TRUST titer, anti-syphilis treatment, serological fixation, Jarisch-Herxheimer reaction