2022 Volume 21 Issue 2 Pages 133-137
A 48-year-old man noticed multiple reddish-brown infiltrated nodules located mainly on his trunk since his thirties. He had atopic dermatitis as a child, after which his symptoms were stable. He was referred to our hospital and considered as atopic dermatitis. He had been treated with topical corticosteroid with temporal improvement and recurrence of symptoms for 13 years. For histopathological diagnosis, we performed a punch biopsy from a reddish-brownish papule at his back. The specimen showed lymphocytes, eosinophils, and plasma cells in the superficial dermis. No storiform fibrosis and obliterative phlebitis were observed. Light chain restriction was not found in the tissue. M proteins and Bence Jones protein were negative. We considered cutaneous plasmacytosis, pseudolymphoma, and IgG4-related disease. Recent studies reported the association amongcutaneous plasmacytosis, pseudolymphoma, and IgG4-related disease. Our patient showed high serum IgG4. The biopsy material revealed IgG4 positivity in 40-60% of IgG positive plasma cells. The absolute IgG4 counts were 40/hpf. Our patient did not fulfill the criteria of the International Consensus Statement in 2011 ; however, he had features of IgG4-related disease. This suggests an oversight in the International Consensus Statement and that the diagnosis of IgG4- related skin disease is still controversial. Skin Research, 21 : 133-137, 2022
