A Diagnostic Pitfall: Secondary Syphilis Mimicking Psoriasis in a Patient With Alcoholic Liver Disease.

Syphilis is a sexually and vertically transmitted infection caused by Treponema pallidum that remains a significant public health concern due to its rising incidence and protean clinical manifestations. The disease is characterized by distinct stages and has the potential to involve multiple organ systems, leading to serious complications if diagnosis and treatment are delayed. Secondary syphilis, in particular, is notorious for its wide spectrum of clinical presentations and its ability to closely mimic numerous dermatologic and systemic conditions, often resulting in diagnostic uncertainty. We present a case of secondary syphilis in a 52-year-old male patient with a known history of chronic psoriasis, whose diffuse papular eruption closely resembled a psoriasiform flare. The clinical picture was further complicated by underlying alcoholic cirrhosis with associated jaundice, which obscured classic cutaneous and systemic features typically associated with secondary syphilis. Initial laboratory evaluation yielded indeterminate serologic findings, contributing to diagnostic delay and highlighting the limitations of relying on a single test in complex clinical scenarios. The coexistence of a preexisting inflammatory skin disorder and chronic liver disease significantly lowered clinical suspicion for syphilis, as the patient's dermatologic findings were initially attributed to an exacerbation of psoriasis. Ultimately, a thorough clinical reassessment, repeat serologic testing, and careful consideration of alternative diagnoses led to the identification of secondary syphilis. This case underscores the diagnostic challenges posed by syphilis in patients with comorbid dermatologic and systemic conditions and illustrates the importance of maintaining a high index of suspicion, even when cutaneous findings appear consistent with an established underlying disease. It also emphasizes the need for routine syphilis screening in at-risk populations and in patients with atypical or refractory skin manifestations. Early recognition and appropriate treatment are critical to preventing disease progression and long-term complications, reinforcing the role of vigilant clinical evaluation in modern medical practice.