(116) Rectal-labial fistula presenting as persistent labial abscess in a 7 week old infant

Background: Pediatric and adolescent gynecologists are frequently consulted for management of labial abscesses in children. Though labial abscesses often resolve with incision and drainage (I&D) and antibiotics, the persistence or recurrence of a labial abscess in an infant warrants consideration of underlying anatomic or immunologic causes.

Case: A healthy 7 week old female with family history of Crohn’s disease presented to the emergency department (ED) with left labial edema and erythema. Translabial ultrasound showed superficial edema and phlegmon without abscess. The patient had resolution of symptoms with intravenous antibiotics, however, re-presented with recurrence of symptoms and exam demonstrating an evolving left labial abscess (image). An I&D was performed in addition to oral antibiotics. The patient again presented to the ED with recurrence of a subcentimeter left labial abscess despite broad spectrum antibiotic therapy. Wound cultures varied from normal flora to candida species, K.oxytoca, R. ornithinolytica, E. faecali. Workup by Gastroenterology (GI) and Immunology did not show immunodeficiency. Exam by General Surgery and an MRI without enteric contrast did not reveal a fistula. An exam under anesthesia (EUA), I&D, superficial wound debridement and irrigation, tissue biopsy and flexible sigmoidoscopy revealed normal recto-colonic mucosa without a fistula. Biopsy showed fibroconnective and adipose tissue with chronic inflammation. The case was followed by Gynecology and ID specialties, however the patient would have recurrence of symptoms after discontinuation of antibiotics. On the fifth presentation, stool and air bubbles were noted emitting from the labial incision during valsalva. A contrast enema showed a narrow fistulous tract from the rectum to the labia. At 5 months old, she underwent an EUA, sigmoidoscopy and placement of a seton with GI and General Surgery services. Two weeks later, she developed a new left labial abscess next to the seton, which was concerning for another rectal-labial fistula and further raised suspicion for very early onset inflammatory bowel disease (VEOIBD). Further imaging and testing did not show evidence of definite diagnosis of VEOIBD. The seton remains in place with plan for removal after 5 months.

Comments: For young patients presenting with persistent or recurrent labial abscess, it is prudent to have a broad differential and consider work up for fistulous tracts and inflammatory bowel disease. Though initial evaluation provided limited information, a multidisciplinary approach was crucial in identifying the diagnosis of rectal-labial fistula in this patient with probable VEOIBD.