August 2019 A 65-year-old male with pruritic skin eruptions
Contributors: Mohammed Saad MBBS PGY-3 Resident Physician, Anatomic Pathology and Clinical Pathology Indiana University School of Medicine Professional Interests: Cytopathology, Gastrointestinal Pathology, Hematopathology and General Surgical pathology Ahmed K. Alomari, FEL, MD Assistant Professor of Clinical Pathology & Laboratory Medicine Indiana University School of Medicine Terrence M. Katona, DO Assistant Professor of Clinical Pathology & Laboratory Medicine Indiana University School of Medicine Clinical history: A 65-year-old man with one-month history of diffuse pruritic eruption involving trunk and lower extremities. The rash was extremely itchy and kept him awake at night. There were no associated constitutional symptoms. His medications included Metoprolol (HTN), Ibuprofen (PRN headache), a daily multivitamin and fish oil. He used Vaseline on his skin which helped mildly. Initial physical examination revealed well-demarcated hyperpigmented and violaceous papules coalescing into larger plaques with some areas of sparing over most of the chest, back, abdomen, and bilateral upper extremities (images 1A,1B). There was a single inflammatory bulla in the left forearm. Initial workup was negative for neoplasia, infections and vitamin deficiencies. Initial biopsy showed mild interface damage with a predominantly perivascular infiltrate and few eosinophils. Despite intramuscular steroid injections, the rash quickly progressed with bullae formation predominantly on extremities (images 2A, 2B). Additional biopsies with direct immunofluorescence were submitted for examination. Additional laboratory findings were positive BP180 and negative BP230. Microscopic examination and immunohistochemistry: Sections from the affected skin showed subepidermal blister with neutrophils and eosinophils; superficial and focally deep perivascular and peri-eccrine lymphoplasmacytic inflammation with occasional eosinophils and parakeratosis. DIF revealed linear and granular C3 with focal linear IgG along the basement membrane zone with shaggy band of fibrinogen. Figures IA-IG.
Image 1A &1B Well-demarcated hyperpigmented and violaceous papules coalescing into larger plaque.
Image 1A &1B
Image 2A & 2B
I-C & I-D A perivascular infiltrate was present with marked eosinophils (I-C & I-D) (H&E, magnification ×200).
(I-E) detection of IgG, (I-F) deposition of complement factor C3 deposition, and shaggy fibrinogen band (I-G) at the dermal-epidermal junction in a punch biopsy from perilesional skin, using direct immunofluorescence microscopy (magnification 200×). (I-E) detection of IgG, (I-F) deposition of complement factor C3 deposition, and shaggy fibrinogen band (I-G) at the dermal-epidermal junction in a punch biopsy from perilesional skin, using direct immunofluorescence microscopy (magnification 200×). August 2019 Final Diagnosis and Discussion |