A 63-year-old white woman with diabetes was referred to us with a 7-year history of ulcerating and very painful NL lesions on her shins, which had gradually enlarged during this period. The patient was a smoker and had a history of well-controlled type 2 insulin-treated diabetes mellitus (hemoglobin A1c proportion, 6.1%) with no additional diabetic complication. Physical examination revealed atrophic, yellow-brown, telangiectatic plaques affecting her lower legs. The lesions had large, deep, and crusting ulcerations (Figure 1). Cutaneous biopsy findings were compatible with NL, and direct immunofluorescence findings were negative. The patient had previously received treatments with topical corticosteroid, topical tacrolimus, hydroxychloroquine, psoralen plus UV-A, and pentoxifylline without any significant clinical response. Owing to recurring ear, nose, and throat infections, CVID was suspected. Immunologic tests revealed a poor response to vaccines (pneumococcus and diphtheria) and reduced serum immunoglobulin concentrations (IgG, IgM, and IgA at 77, 23, and 40 mg/dL, respectively). No secondary cause of hypogammaglobulinemia was observed (no history of immunosuppressive therapy, digestive symptoms of inflammatory disease, nor evidence for neoplasia by thoraco-abdominal computed tomographic scan and flow cytometry).