Secondary Syphilis in Man: Prozone Effect

Abstract

Introduction: Syphilis consists in a systemic infect contagious pathology with a chronic character. The etiological agent consists of an anaerobic spirochete bacterium, Treponema pallidum. Laboratory diagnosis can be made through a direct investigation of the etiologic agent or non-treponemal (VDRL) and treponemal (FTA-Abs) serological tests. False-negative results are rare. Objectives: The present report presents a rare case of a man with a secondary syphilis syndrome who was initially undiagnosed due to the prozone effect, since he presented VDRL in low titers, and was later confirmed with a new diluted serum sample and VDRL and FTA-Abs, which were positive. Conclusion: A close look should be given to patients who, although the clinical condition is compatible, complementary exams may not be, and clinical cases should be carefully evaluated so that the patient is not treated late.