Pelvic abscess is a collection of pus in the pelvis, typically occurring following lower abdominal surgical procedures, or as a complication of pelvic inflammatory disease (PID), appendicitis, or lower genital tract infections.^[1] Signs and symptoms include a high fever, pelvic mass, vaginal bleeding or discharge, and lower abdominal pain.^[1] It can lead to sepsis and death.^[1]

Blood tests typically show a raised white cell count.^[1] Other tests generally include urine pregnancy test, blood and exudate culture, and vaginal wet mount.^[1] Ultrasound, CT-scan or MRI may be used to locate the abscess and assess its dimensions.^[1] Treatment is with antibiotics and drainage of the abscess; typically guided by ultrasound or CT.^[3] Endoscopic ultrasound (EUS) is a minimally invasive alternative method.^[3]

Signs and symptoms

Signs and symptoms include a high fever, pelvic mass, vaginal bleeding or discharge, and lower abdominal pain.^[1] There may be urinary frequency, diarrhoea, or persistent feeling of needing to pass stool.^[4] Other symptoms may include fatigue, nausea, and vomiting.^[2] Clinical features might not be apparent until the pelvic abscess has grown in size.^[2] The lower abdomen is generally tender; one or both sides.^[2] A bulging of the front wall of the rectum might be felt on digital examination via the rectum or vagina.^[2]

Complications include sepsis and peritonitis.^[1] In the longterm, a fistula may develop.^[2]

Cause and mechanism

Pelvic abscess typically occurs following gynecological surgery and abdominal surgery; hysterectomy, laparotomy, caesarian section, and induced abortion.^[1] It may occur as a complication of pelvic inflammatory disease (PID), appendicitis, diverticulitis, inflammatory bowel disease (IBD), trauma, pelvic organ cancer, or lower genital tract infections.^[1][3] The abscess may be in the pouch of Douglas, fallopian tube, ovary, or parametrium.^[1] It begins as inflammation or a collection of blood in the pelvis.^[1] Other risk factors include immunodeficiency, pregnancy, hydrosalpinx, endometrioma, poorly controlled diabetes, kidney disease, obesity, and genital tract abnormalities.^[1][2] Opening the rectum to resect a rectal cancer may lead to developing a pelvic abscess.^[3]

Females

PID in females may lead to a tubo-ovarian abscess, where the abscess may be in the fallopian tube or ovary.^[1][2]

Children

In children, it is more frequently associated with IBD and appendicitis.^[5]

Diagnosis

Blood tests typically show a raised white cell count, often with a high ESR and C-reactive protein.^[1] Other tests generally include urine pregnancy test, blood and exudate culture, and vaginal wet mount.^[1] Medical imaging to assess the dimensions and locate the abscess may include ultrasound, CT-scan or MRI.^[1]

Differential

Other conditions that appear similar include ectopic pregnancy, PID, appendicitis, kidney stone, bowel obstruction, and sepsis following miscarriage or termination of pregnancy.^[1]

Treatment

Treatment is with antibiotics and drainage of the abscess; typically guided by ultrasound or CT, through the skin, via the rectum, or transvaginal routes.^[3] Occasionally antibiotics may be used without surgery; if the abscess is at a very stage and small.^[2] Until sensitivities are received, a broad spectrum antibiotic is generally required.^[2] Sometimes, a laparotomy of laparoscopy is required.^[2]

Endoscopic ultrasound (EUS) is a minimally invasive alternative method.^[3] Treatment also includes adequate hydration.^[1]

Further surgery such as is sometimes required to treat the underlying cause; such as salpingo-oophorectomy for tubo-ovarian abscess.^[2]

Outcome

Pelvic abscess responds well to antibiotics and hydration.^[1] The outcome is less successful in the presence of fistula.^[2]

Epidemiology

It is uncommon.^[2] The incidence of pelvic abscess is less than 1% in an individual undergoing obstetric and gynecological operative procedure.^[3]