Case Presentation:

A 16 year old, previously healthy male, presented with a four day history of enlarging left inguinal mass. The patient initially reported falling off a scooter with a handlebar injury to his left groin three weeks prior to admission. Symptoms began with a “small bump” in the groin that rapidly grew in size. The patient reported minor pain with the mass, however, the patient’s mother noted the patient limping and leaning forward for several days prior to admission. The patient denied history of fevers but was febrile on admission. He reported a 25lb weight loss over the past the month. He denied abdominal pain, decreased appetite, change in bowel or bladder habits, or recent travel. Physical exam was notable for a 5cm x 10cm firm, indurated, mildly tender left inguinal mass, with overlying erythema. Laboratory analysis was notable for anemia (Hb 8.2), leukocytosis (20.2) and elevated CRP (8.1, normal range 0-0.99) and ESR (>140, normal range 0-15). Abdominal CT revealed a low-attenuation collection with rim enhancement within the left anterior abdominal wall along the rectus muscle measuring 10.2 x 4.6 x 8.5 cm suggestive of an abscess. MRI abdomen confirmed the findings of a left phlegmon emanating from the psoas with extensive swelling of the left iliopsoas and iliacus muscle and contiguous fluid collection involving the left anterior abdominal wall musculature. Vancomycin and meropenem were started empirically. A 3 cm incision inferior to the anterior superior iliac spine yielded immediate evacuation of 300 cc of purulent fluid from the abdominal wall abscess tracking to the psoas muscle.

Wound culture grew beaded gram-positive rods, later confirmed to be Actinomyces Israelii. Further history revealed that the patient was experiencing bullying and that he was pushed to the ground and kicked about 1 month prior to admission. Antibiotics were narrowed to an extended course of clindamycin and patient was seen by social work to address the bullying. 


Actinomyces is a common bacterium in gut microbiota. Risk factors include diverticular or appendiceal mucosal damage and trauma, which the patient experienced 1 month prior. Disease tends to remain localized and spread contiguously, disregarding tissue planes, consistent with the MRI images. Patient presentation was also consistent with abdominal actinomycosis given his indolent course of weight loss, fever, abdominal pain, and palpable mass. Similarly, common lab abnormalities including anemia and leukocytosis, were seen. Unfortunately, given and the lack of documentation of the bullying, unclear onset of symptoms, and delayed presentation it is difficult to correlate the bullying incident to the infection.  

The differential included nocardiosis which is also identified as beading gram positive rods on gram stain. However nocardia bacteremia is rare and not commonly found as commensal bacteria. Additionally, this patient lacks risk factors in that he did not have an endovascular venous catheter nor was he immunocompromised.


This clinical vignette represents an atypical case of abdominal actinomycosis with an unclear etiology suspicious for trauma in an otherwise healthy male. Abdominal abscesses usually present in a more acute manner, but it is important to consider this diagnosis in patients with a new onset limp and generalized B symptoms. Furthermore, this is a reminder of possible physical and psychological consequences of bullying and the importance of primary care providers acting as community advocates for anti-bullying.