We present a case of acute flank and groin pain resulting from a ruptu
red left iliac artery with pseudoaneurysm in a patient with previously
undiagnosed Ehlers-Danlos syndrome (EDS). EDS is an uncommon, heterog
eneous disease of abnormal collagen production with potentially fatal
sequelae. The nine major types of EDS have varying clinical manifestat
ions and degrees of severity. Type IV EDS is of special concern in tha
t it is frequently associated with life-threatening vascular complicat
ions such as arterial aneurysm formation with rupture and dissection.
EDS should be suspected in young people with vascular complications, r
ecurrent joint dislocations, or fragile skin. In patients with known E
DS, abdominal, flank, or pelvic pain should be investigated promptly t
o rule out life-threatening complications involving the vascular syste
m, gastrointestinal tract, or gravid uterus.