The prozone phenomenon in syphilis testing refers to a false negative response resulting from overwhelming antibody titers which interfere with the proper formation of the antigen-antibody lattice network necessary to visualize a positive flocculation test. This prozone effect in syphilis testing can be expected in cases of disproportionately high antibody titers, such as secondary syphilis, or with human immunodeficiency virus (HIV) coinfection. Clinicians need to remain familiar with the protean manifestations of syphilis to be able to exclude the prozone phenomenon.
Portions of this issue may be available for CME credit. Please visit the SMA Education Center for a complete listing of current Southern Medical Journal activities, as well as other SMA educational offerings.