[Bullous paraneoplastic acrokeratosis]

Area of Science:

• Dermatology
• Oncology
• Immunology

Background:

• Bazex's syndrome, or acrokeratosis paraneoplastica, is a rare paraneoplastic condition.
• Bullous lesions on the extremities are an uncommon manifestation of Bazex's syndrome.

Observation:

• A 65-year-old male with a history of alcohol and smoking presented with acrokeratosis paraneoplastica and a cervical lymph node mass, later diagnosed as piriform sinus epidermoid carcinoma.
• The patient developed worsening acral keratotic lesions, accompanied by painful, hemorrhagic bullous lesions on his feet and toes.
• Histopathology revealed subepidermal blisters with eosinophils, and direct immunofluorescence showed C3, IgA, and IgM deposits.

Findings:

• The patient exhibited blood eosinophilia and elevated IgE levels.
• Treatment with radiation and chemotherapy for the epidermoid carcinoma resulted in the healing of bullous lesions and regression of keratotic lesions.
• The bullous lesions mimicked autoimmune bullous diseases, suggesting an immunological basis.

Implications:

• This case highlights that bullous lesions, though rare, can be an early sign of Bazex's syndrome.
• The findings suggest an immunological reaction involving the dermal-epidermal junction and eosinophils in the pathogenesis of these bullous lesions.
• Successful cancer treatment led to the resolution of paraneoplastic dermatological manifestations.