We read with great interest the experience of Shweikeh et al. who encountered a case of coinciding systemic polyarteritis nodosa (sPAN) and Crohn's disease (CD). 1 A recent similar experience at our hospital highlights several important lessons.A 32-year-old Caucasian man with severe refractory CD presented profoundly unwell with a 5-day history of recurrent fever, persistent bloody diarrhea, nonproductive cough and cachexia, associated with feet hyperesthesia. He was a nonsmoker and nondrinker, with a strong family history of autoimmune disease (CD, two maternal cousins; coeliac disease, mother and brother; juvenile idiopathic arthritis, maternal cousin). He developed significant weight loss while his overall health deteriorated significantly over the course of 9 months with four hospital admissions to treat his active CD, which was further complicated 3 months prior to his most recent admission by fibrotic strictures necessitating a right hemicolectomy.He was on mesalazine, azathioprine and adalimumab, which were held preoperatively in view of avoiding postoperative complications and in assisting recovery.On admission, he appeared weak, tachycardic (148 beats/minute; with an elevated diastolic pressure of 100 mmHg) and was mildly febrile. Oxygen saturation was 97% on room air with a respiratory rate of 18 breaths/minute. Chest examination was unremarkable. Abdomen was soft nondistended and without palpable mass, but he was tender at the right iliac fossa. He had no evidence of inflammatory arthritis and neurological examination was unremarkable. Electrocardiogram demonstrated sinus tachycardia without any other abnormality.