ABSTRACT
The diversity of the cutaneous manifestations of syphilis and the ability of the spirochete to evade diagnosis have been well documented by medical literature. However, what triggers the onset of secondary syphilis is not yet clear because of difficulties studying the bacterium. Our case describes the onset of a heterogeneous rash (or coexisting rashes) that presented the day after vaccination with the Moderna mRNA-1273 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. The potential etiologies of the patient's rash: A vaccine reaction, reactivation of chronic spontaneous urticaria, or a physical sign of syphilis itself are then reviewed. The potential for the Moderna coronavirus disease 2019 (COVID-19) vaccine to be the catalyst of this patient's cutaneous manifestations of his immune system responses is also hypothesized.