Background: Spontaneous rupture of the spleen occurs in 0.1-0.2% of patients with infectious mononucleosis and is associated with a high mortality (9-13%). Rupture is not normally preceded by a trauma.
Case description: A previously healthy 17- year-old boy presented at the Emergency Department with acute onset of pain in his left upper abdomen and left shoulder. Initially he showed no signs of shock, but he did have signs of an acute abdomen. In addition, spots of pus were seen on both pharyngeal arches. Urgent ultrasound showed free fluid in his abdomen, and CT scan revealed active bleeding from the spleen. The patient underwent embolisation of the splenic artery. Serological investigations were positive for a recent infection with the Epstein-Barr virus.
Conclusion: In young patients with signs of acute abdomen and pharyngitis, in the absence of prior trauma, spontaneous rupture of the spleen should be considered. The severity of a rupture of the spleen may initially be underestimated as haemodynamic instability and signs of shock occur only at a late stage.