Direct immunofluorescence findings in cicatricial alopecia: A retrospective study of 155 cases.

Objectives: To study the direct immunofluorescence (DIF) in cicatricial alopecia (CA) patients.

Materials And Methods: Approximately, 155 skin biopsies from CA patients examined over 7 years (2009-2015). Special stains and Hematoxylin and Eosin were performed, and final histopathological diagnosis was made. DIF (against anti-IgG, IgM, C3, IgA, and fibrinogen) on all these cases and patterns were noted. The descriptive statistics were applied along with ANOVA test.

Results: Approximately, 155 patients with Male: Female = 1.24:1, age 7-65 years. In total, 57 cases were of Lichen planopilaris (LPP; 36.7%), 22 Lichen planus (LP; 14.2%), 22 Psuedopalade of Brocq (PPB; 14.2%),16 discoid lupus erythematosus (DLE; 10.3%), 8 end-stage scarring alopecia (ESSA; 5.2%), 2 cases each of Fungal folliculitis (FF), and Folliculitis decalvans (FD; 1.3% each), and in 26 cases, no specific diagnosis could be reached were collectively kept in the category of non-specific findings (NSP; 16.7%). On DIF: LPP positive for IgG = 4 cases (7%), IgM = 26 (45%), IgA = 11 (19.3%), C3 = 16 (28.1%), and fibrinogen = 11 (19.3%). LP positive for IgG = 2 (9%), IgM = 18 (81%), IgA = 2 (9.1%), C3 = 10 (45%), and fibrinogen = 1 (4.5%). DLE positive for IgG = 6 (37%), IgM = 8 (50%), IgA = 1 (6.3%), C3 = 9 (56%), and fibrinogen = 1 (4.5%).

Limitations: Because this was a retrospective study, clinical follow-up and treatment history of the patient could not be retrieved.

Conclusions: IgG positivity helps significantly in differentiating LPP from DLE (P 0.004) and NSP from DLE (P 0.005). IgM positivity helps significantly in differentiating LPP from LP (P 0.04), LP from PPB (P 0.00) and NSP (P 0.00). C3 positivity helps significantly in differentiating PPB from DLE (P 0.02).