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What is Fish Net pattern in pemphigus vulgaris is seen in which of the following tests? and explain in detail?
Pemphigus vulgaris causes intraepithelial bullae formation and results in loss of cohesiveness or acantholysis. Due to this, clumps of epithelial cells are found lying free in the vesicular space, known as Tzanck cells. These changes are seen in cytological smears also known as the Tzanck smear or Tzanck test. The fluid in most vesicles has scarce inflammatory cell infiltration.
Direct Immunoftuorescence predominantly demonstrates the presence of IgG in combination with IgM, IgA, C3. Direct Immunofluorescence reveals a typical fish net pattern or chicken wire pattern of IgG antibodies against desmoglein 1 or 3 even in the perilesional skin.