Pregnant Woman With Crohn's Disease Experiences Perianal Pain

A 29-year-old woman who was 35 weeks' pregnant presented to the emergency department (ED) with perianal pain that had been worsening over the past few days. The patient explained that she had presented to the obstetrics department 5 days earlier when the pain -- which was mild at the time -- had developed; at that time, after a reassuring clinical examination, she had been prescribed pain medications and was discharged.

The patient's history included Crohn's disease involving the left colon and perianal fistula, which had been diagnosed about 10 years previously and was currently in clinical remission. She had been taking infliximab (Remicade) for the past year, including throughout her pregnancy. Prior to starting infliximab, the patient had developed a perianal abscess that had been drained, and she had undergone an unsuccessful trial of treatment with certolizumab pegol (Cimzia).

On presentation to the ED, the patient was otherwise free of clinical comorbidities. She was admitted for fetal monitoring and colorectal evaluation.

Clinicians performed a physical examination, which showed unremarkable findings, except for an anal stricture. Findings of an initial workup included an elevated white blood cell count and C-reactive protein level. A perineal ultrasound revealed a 9-mL fluid collection. Clinicians started the patient on intravenous ceftriaxone and metronidazole to treat a small perianal abscess.

That night, the patient required an emergency cesarean section due to fetal distress. The surgery was uneventful, and the baby recovered well. At about 12 hours' postpartum, the patient developed tachycardia and hypotension. Her perianal pain continued to worsen; a proctology examination identified diffuse hyperemia with swelling of the vulva and purple discoloration of the skin.

Clinicians suspected that the patient had Fournier's gangrene, and performed wide drainage and debridement. During surgery, they noted necrosis of the ischiorectal fat with foul-smelling purulent discharge, and debrided the affected tissue to expose the underlying healthy tissue. Anoscopy revealed rectal ulcers and a fistulous opening with purulent discharge in the distal rectum, although necrosis did not involve the anal sphincter.

Clinicians performed a laparoscopic loop ileostomy with intraoperative colonic lavage through the distal limb, followed by vacuum-assisted therapy and placement of hydrocolloid paste in the perineal defect.

Lab cultures revealed the presence of polymicrobial infection with Escherichia coli, Citrobacter freundii complex, and Candida albicans, and clinicians made appropriate adjustments to the patient's antibiotic regimen.

Three days later, the patient was discharged from the intensive care unit. On postoperative day 14, after four debridements and vacuum-assisted therapy exchanges, the team closed the perineal defect with a unilateral medial thigh advancement flap, and placed a draining seton in the suprasphincteric fistula. After 28 days in the hospital, the patient was discharged and recovered with no further problems.

At a 3-month follow-up examination, clinicians found that the medial thigh flap had healed completely and there was no evidence of infection. The seton was left in place, and the patient resumed treatment with infliximab. Clinicians planned a reverse ileostomy.

Discussion

Clinicians reporting this uncommon case of Fournier's gangrene in a young pregnant woman with a 10-year history of Crohn's disease noted that delayed recognition of this rapidly progressive necrotizing infection of the perineum has been associated with higher mortality.

Originally described in 1883 as an idiopathic fulminant infection of the scrotum by the French dermatologist Jean Alfred Fournier, Fournier's gangrene is now recognized to be most commonly related to local trauma or urinary and colorectal infections in the setting of immunosuppression, the authors noted. The condition is only rarely "associated with inflammatory bowel disease (IBD) or pregnancy, although both conditions can affect the immune system."

While features of Crohn's disease have been reported to differ in adult-onset versus pediatric-onset patients, with the latter at higher risk of complications, one study found that the cumulative risks of intestinal stricture, intestinal perforation, and perianal fistula were similar regardless of age of onset, with approximately 75% and 78% of these respective groups free of perianal disease (P=0.35) at 10 years.

The authors noted that although perianal disease is relatively common in IBD, affecting up to one-third of patients with Crohn's disease, it "rarely progresses to necrotizing infections," adding that none of the other five reported IBD-related cases of Fournier's gangrene occurred during pregnancy.

Emphasizing the importance of treating Fournier's gangrene early, the authors cautioned that "the initial clinical picture may be misleading," with only a small proportion of patients presenting with clinical signs of tissue necrosis with crepitus and discoloration of the skin. Pregnancy is often associated with mild pain, they added, thus its potential significance may be "unappreciated by the attending physician," as it was for this patient, who was initially discharged with painkillers.

IBD is associated with complex immunological changes related to the disease itself, malnourishment, or treatment with immunosuppressive and anti-tumor necrosis factor therapies, which can leave patients at increased risk for opportunistic infections, they noted, as was the case for their patient, who was taking infliximab.

However, development of Fournier's gangrene "is more commonly associated with diabetes, HIV, alcoholism, and cancer," they pointed out. According to a recent review of 108 articles, the most frequent comorbidities related to Fournier's gangrene are diabetes mellitus (31.7%), hypertension (26.1%), obesity (12.1%), and anemia (10%).

Of the rare reports of Fournier's gangrene during pregnancy, none were related to IBD. Two involved severe and fatal infections related to premature birth, one involved concurrent emergency cesarean section and debridement, and one involved fulminant infection that developed a few hours after birth.

"In our patient, the primary source of infection was present before delivery and caused oligohydramnios, which was not present in the prenatal ultrasound and is a sign of fetal distress," the authors explained. The reduced immunity that occurs in pregnancy may also have contributed to their patient's Fournier's gangrene, they added.

Fournier's gangrene is generally managed with extensive debridement and antibiotics, they noted, while use of a diverting stoma is controversial but may have a role in patients with rectal perforation, fistulas, or fecal incontinence. Given the colorectal origin in this case, early diversion to control sepsis and facilitate use of vacuum-assisted therapy seemed prudent, the authors said.

"Since the patient had a diseased left colon from Crohn's colitis, our preferred option was a loop ileostomy with distal washout," since the alternative loop-transverse colostomy "is associated with higher risk of troublesome prolapse and parastomal hernias," they wrote.

Vacuum-assisted therapy in the perineum is challenging because of "loss of adherence and local contamination requiring frequent dressing changes in the OR," they observed, pointing out that use of hydrocolloid paste may help the plastic film adhere to the tissue. Negative-pressure therapy is useful to control local infection and promote tissue healing, they added.

Extensive debridement can result in tissue loss that "often leaves primary closure unfeasible," they noted, advising that after all necrotic tissue has been removed and healthy tissue is accessible, "reconstruction with regional flaps is safe."

Patients with Crohn's disease require special care "due to impaired healing of the perineum in active disease," the authors wrote. Given their patient's perianal abscess and fistula, the team placed a seton in the fistula tract through the flap to avoid recurrent abscess.

Managing Fournier's gangrene in a patient during pregnancy requires "a multidisciplinary team to ensure the care of the baby and to facilitate early debridement and intestinal diversion," the authors concluded. They urged clinicians not to dismiss perianal pain, since this "may be the only symptom in an immunosuppressed patient."

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