A 53-year-old morbidly obese woman diagnosed with Crohn disease 3 years earlier was being treated with adalimumab (40 mg per 15 days) and methotrexate (15 mg per week). She presented with severe fatigue and a 30-kg weight loss over the previous 2 months, as well as fever and multiple new-onset ulceronecrotic skin lesions on her lower limbs. Skin biopsy disclosed microvascular thrombosis and a prominent eosinophilic infiltrate in the dermis. On admission, severe pancytopenia was found: hemoglobin, 44 g/L; mean corpuscular volume, 100 fL; leukocytes, 0.58 × 10 9/L (eosinophils, 0.17 × 10 9/L); and platelets, 36 × 10 9/L. The bone marrow aspirate (BMA) was hypercellular with severe dyshemopoiesis, 0.5% granulopoiesis, and 31% eosinophils (confirmed by flow cytometry). Widespread dysplasia was observed in eosinophils, with 1.5% of eosinophils having ring-shaped nuclei as highlighted (BMA; panels A-I: original magnification ×1000, May-Grünwald-Giemsa stain) (courtesy of Ricardo Bernal, Seville, Spain). Finally, the patient’s pancytopenia recovered on discontinuing adalimumab and methotrexate.Peripheral eosinophilia with an eosinophilic infiltrate affecting skin lesions has been described with anti–tumor necrosis factor α therapy such as adalimumab. This case illustrates a significant bone marrow eosinophilia and the unusual observation of ring-shaped nuclei in eosinophils. These anomalies may be associated with the administration of adalimumab or its combination with methotrexate.