Spongiotic Pattern in Pemphigus: A Retrospective Observational Single-Center Study.

Area of Science:

• Dermatology
• Immunopathology
• Histopathology

Background:

• Pemphigus is an autoimmune blistering disease targeting epidermal desmosomal proteins.
• Pemphigus can present with spongiosis and vesiculation, mimicking eczema, especially when acantholysis is absent.
• Accurate diagnosis is crucial to differentiate pemphigus from other spongiotic dermatoses.

Purpose of the Study:

• To identify characteristic spongiosis patterns in pemphigus.
• To differentiate pemphigus with spongiosis from eczema using histological features.
• To provide diagnostic clues for pemphigus when acantholysis is not evident.

Main Methods:

• Retrospective, observational, single-center study of immunopathologically diagnosed pemphigus specimens (2001-2020).
• Analysis of histological features including vesiculation, acantholysis, spongiosis, and inflammatory infiltrates in pemphigus with spongiosis.
• Comparison with control cases of spongiotic dermatitis.

Main Results:

• 41 out of 99 pemphigus specimens showed spongiosis; 25% lacked acantholysis.
• Spongiosis in the mid-to-lower epidermis, exocytosis (neutrophils/eosinophils), and specific dermal infiltrates were more frequent in pemphigus.
• Absence of Langerhans cell microabscesses was significantly associated with pemphigus.

Conclusions:

• Spongiosis in pemphigus can histologically resemble eczema, particularly in cases lacking acantholysis.
• Subtle histological findings identified in this study can aid in suspecting pemphigus.
• Direct immunofluorescence remains essential for confirming pemphigus diagnosis in ambiguous cases.