Pathology · single question
What is the best method to diagnose this condition?
Show answer and explanation
Correct answer: A. Direct immunofluorescence (DIF)
Autoimmune vesiculobullous diseases (pemphigus vulgaris, mucous membrane pemphigoid, etc.) are definitively diagnosed by histopathology PLUS direct immunofluorescence on perilesional tissue. DIF reveals the location and type of immune-complex deposition (intraepithelial net-like in pemphigus; linear at the basement membrane in pemphigoid).