Mesenteric Lymphadenitis Due to COVID-19 in an Adult.

Coronavirus disease 2019 (COVID-19) is an infectious disease that can present with a wide range of symptoms. Abdominal pain is less common than other symptoms but is more frequent among patients with severe disease. Various abdominal imaging findings are described in the literature for children and adults with COVID-19 infection. Mesenteric lymphadenopathy is reported in pediatric patients with COVID-19 gastrointestinal infection. It is very rarely reported in the adult population. We report a case of an adult male with multiple risk factors, who presented with severe abdominal pain and tenderness in the right inguinal fossa. He was evaluated for differential diagnosis of acute appendicitis, renal colic, diabetic ketoacidosis (DKA), and COVID-19. His investigations showed normal laboratory tests and a normal chest radiograph. His CT abdomen showed a normal appendix and multiple prominent mesenteric lymph nodes. His COVID-19 PCR was positive. He was discharged after pain relief with home isolation instructions and symptomatic management. Our case represents an atypical clinical presentation of COVID-19 infection in many ways. His laboratory investigations were not suggestive of COVID-19. Our patient's abdominal imaging findings represent a rare association of COVID-19 with mesenteric lymphadenitis in adults. The clinical course of our patient was smooth after discharge and he did not develop any complications of COVID-19 despite multiple risk factors. Our case reminds the significance of keeping broad diagnostic differentials in the emergency department. Although mesenteric lymphadenitis is often a self-limiting condition affecting children and young adults, it is the most frequent alternative diagnosis of acute appendicitis and intussusception. Mesenteric lymphadenitis can be the sole atypical presentation of COVID-19 in adults. Atypical presentations are not uncommon due to the scarcity of data on this evolving disease.