Revista da Sociedade Portuguesa de Dermatologia e Venereologia (Sep 2020)
Syphilitic Balanitis of Follmann: Laboratory Pitfalls
Abstract
We report a case of early syphilis, presenting as balanitis and papular syphilides in an HIV-infected patient, with a previous history of syphilis infection, which demonstrated a false negative VDRL testing due to a prozone phenomenon. This false negative response results from overwhelming antibody titers, which interfere with the proper formation of the antigen-antibody lattice network, necessary to visualize a positive flocculation test.
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