[Comparison of complement fixation and Tzanck smear tests for the diagnosis of herpes labialis]

In this study, the serum antibody titer of Herpes simplex virus type 1 (HSV-1) in 82 patients with herpes labialis and 100 controls was determined using the complement fixation test. In own experience, the Tzanck smear test (reported to be an aid in the diagnosis of HSV infection) was of no value. In comparison to patients in an early stage of infection, convalescent patients had an antibody titer that was 4 or more times higher (1/64-1/256). Fifty-eight percent of the control group was negative. In own opinion, the variation in titer between the acute and convalescent stages in Herpes simplex cases would be of particular value in diagnosing cases of urethritis, cystitis encephalitis, meningitis, conjunctivitis, primary and recurrent eczema herpeticum and erythema multiforme when HSV is suspected to play a role in the etiology.