Pyoderma gangrenosum associated with subcorneal pustular dermatosis and IgA myeloma.

We report a 57-year-old woman with a 12-year history of ulcerative pyoderma gangrenosum (PG). Five years after the onset of PG, she developed subcorneal pustular dermatosis (SPD) and biclonal IgA and IgG gammopathy. She developed PG at two bone-marrow biopsy sites, showing pathergy. Finally, she developed multiple myeloma. Although PG and SPD may occur without associated underlying malignancy, these patients should be followed up for any prospective malignancy because of the association between these disorders.