A case of "essential" cryoglobulinemia was initially misdiagnosed as factitial ulceration. The abnormal protein, not demonstrable on routine electrophoresis, was characterized as a macrocryoglobulin. A biologic false-positive reaction occurred with the venereal disease research laboratory test for syphilis (VDRL), and the Kolmer and fluorescent treponemal antibody (FTA-200) tests, but the Reiter protein complement fixation test (RPCF), fluorescent treponemal antibody test with serum absorbed by Reiter protein sonicate (FTA-abs), and Treponema pallidum immobilization test (TPI) were nonreactive. Pitfalls in diagnosis of cryoglobulinemia are enumerated. Clinical criteria for factitial ulceration are applied.
BAUGHMAN RD, SOMMER RG. Cryoglobulinemia Presenting as "Factitial Ulceration". Arch Dermatol. 1966;94(6):725–731. doi:10.1001/archderm.1966.01600300049011