Retrosternal abscess after trigger point injections in a pregnant woman: a case report

Although retrosternal abscess is a well known complication of sternotomy and intravenous drug abuse, to date it has not been described as a consequence of trigger point injections. There are reported cases of serious complications as a result of this procedure including epidural abscess, necrotizing fasciitis, osteomyelitis and gas gangrene.

A 37-year-old African-American woman, who was 20 weeks pregnant, presented to our emergency room with complaints of progressively worsening chest pain and shortness of breath over the course of the last two months. She was undergoing trigger point injections at multiple different sites including the sternoclavicular joint for chest pain and dystonia. Two years previously she had developed a left-sided pneumothorax as a result of this procedure, requiring chest tube placement and subsequent pleurodesis. Her vital signs in our emergency room were normal except for resting tachycardia, with a pulse of 100 beats per minute. A physical examination revealed swelling and tenderness of the sternal notch with tenderness to palpation over the left sternoclavicular joint. Laboratory data was significant for a white blood count of 13.3 × 10⁹/L with 82% granulocytes. A chest radiograph revealed left basilar scarring with blunting of the left costophrenic angle. A computed tomography angiogram showed a 4.7 cm abscess in the retrosternal region behind the manubrium with associated sclerosis and cortical irregularity of the manubrium and left clavicle.

Trigger point injection is generally considered very safe. However, there are reported cases of serious complications as a result of this procedure. A computed tomography scan of the chest should strongly be considered in the evaluation of chest pain and shortness of breath of unclear etiology in patients with even a remote history of trigger point injections.