Role of direct immunofluorescence on Tzanck smear and plucked hair in the diagnosis of pemphigus vulgaris

Objective To determine the diagnostic value of direct immunofluorescence (DIF) findings on Tzanck smear and plucked hair in patients of pemphigus vulgaris and to compare the diagnostic value of both the tests. Methods Thirty consecutive patients of pemphigus vulgaris confirmed histopathologically were enrolled in the study. Tzanck smear from the blisters/ erosions was performed. Hair were plucked in a similar manner to that of trichogram. Approximately, 4 to 5 selected anagen hair were processed. Both the Tzanck smear and hair were stained with antihuman IgG, IgM, IgA and C3 fluorescein isothiocyanate (FITC) conjugate. DIF findings were recorded and compared. Results Out of 30 patients, there were 21 (70%) males and 9 (30%) females. DIF was positive on Tzanck smear in 23 (76.7%) patients. Intercellular deposition of IgG was seen in the outer root sheath of anagen hair in 27 out of 30 (90%) patients. Conclusion DIF on Tzanck smear and plucked hair is a simple, painless and non-invasive test in diagnosing pemphigus vulgaris. DIF on hair is more reliable as compared to DIF on Tzanck smear.