Peristomal Punctate Pemphigus.

Area of Science:

• Dermatology
• Immunology
• Pathology

Background:

• Cutaneous reactions around abdominal stoma sites are common, with irritant, allergic, infectious, or traumatic causes.
• Pemphigus, a group of autoimmune vesiculobullous skin disorders, is an uncommon cause of peristomal dermatosis.
• Direct immunofluorescence (DIF) in pemphigus typically shows continuous intercellular IgG deposition, though a punctate pattern is also recognized but underreported.

Observation:

• A 58-year-old man with a colostomy presented with a pruritic, erythematous, crusted plaque around his stoma.
• Histopathology revealed subcorneal acantholytic dermatitis, with negative fungal stains.
• Direct immunofluorescence (DIF) demonstrated IgG and C3 in a punctate intercellular pattern.

Findings:

• The patient was diagnosed with peristomal pemphigus foliaceous based on clinical presentation and DIF findings.
• This case illustrates a rare presentation of pemphigus with a punctate intercellular IgG deposition pattern.
• The punctate pattern of IgG deposition in pemphigus is underreported and its clinical significance is not well understood.

Implications:

• This case expands the differential diagnosis for peristomal dermatoses to include rare autoimmune conditions like pemphigus.
• Increased awareness of punctate pemphigus as a cause of peristomal skin reactions is crucial for accurate diagnosis and management.
• Further research into the punctate IgG deposition pattern in pemphigus may elucidate its specific implications in autoimmune blistering diseases.