Epiploic appendagitis (EA) is a self-limiting, non-surgical condition causing acute abdominal inflammation. It involves small fatty structures within the abdomen and often mimics more severe causes of pain, such as appendicitis or diverticulitis. Despite the intense, sudden pain it causes, EA is considered benign and typically resolves on its own. Understanding the mechanisms behind this inflammation is important to prevent misdiagnosis.
Understanding Epiploic Appendages
Epiploic appendagitis is caused by inflammation of epiploic appendages, which are tiny, fat-filled pouches attached to the large intestine. These structures measure 0.5 to 5 centimeters in length and hang from the outside surface of the colon. They are protrusions of fat-covered peritoneum connected to the colon by a small vascular stalk. While their exact purpose is unknown, they may provide cushioning or play a minor role in immune function. The slender stalk makes these fatty lobules vulnerable to mechanical issues, which leads to inflammation.
The Primary Mechanism of Inflammation
The event that directly causes epiploic appendagitis is an interruption of the blood supply to an appendage, leading to tissue death and inflammation. This lack of blood flow, known as ischemia, is most frequently initiated by torsion, where the appendage twists completely around its narrow vascular stalk. The twisting pinches off the blood vessels, causing the appendage to become engorged and ischemic. This results in aseptic fat necrosis—the death of the fatty tissue—which triggers the intense inflammatory response.
A less common mechanism is thrombosis, the spontaneous formation of a blood clot within the small draining vein. Both torsion and thrombosis cause ischemic infarction and sterile necrosis, which is the source of the acute, localized abdominal pain.
Factors Increasing Susceptibility
Several factors increase susceptibility to the torsion or thrombosis that causes epiploic appendagitis. Anatomical variations, such as longer or more pendulous appendages, are more likely to twist on their narrow pedicle. Since the appendages are composed of fat, conditions like obesity that increase visceral fat can enlarge these structures and predispose them to torsion. The condition most often affects middle-aged adults, particularly those in their fourth or fifth decade of life. Strenuous or sudden physical activity is another contributing factor, as rapid body movements may mechanically induce the twisting of the appendages.
How Epiploic Appendagitis is Managed
The management of epiploic appendagitis is nearly always conservative, reflecting its benign and self-limiting nature. Since the inflammation is caused by sterile fat necrosis and not a bacterial infection, antibiotic therapy is generally not indicated. The primary focus of treatment is the effective control of pain and discomfort, typically using Nonsteroidal Anti-inflammatory Drugs (NSAIDs). Symptoms usually resolve spontaneously within a week, though they may occasionally last up to four weeks. Accurate diagnosis prevents unnecessary hospital admissions and surgical interventions required for conditions it mimics, such as appendicitis or diverticulitis.