From the Guidelines
Ulcerative colitis (UC) can indeed exhibit skip lesions in the colon, although this is not a typical characteristic of the disease.
Key Characteristics of Skip Lesions in UC
- Skip lesions are areas of inflammation interspersed with normal-appearing mucosa, which can sometimes make diagnosis and treatment challenging 1.
- The presence of appendiceal skip lesions has been reported in up to 75% of patients with UC, and has been associated with a more responsive course and a higher risk of pouchitis after ileal pouch anastomosis 1.
- In some cases, UC can present with patchy inflammation in the caecum, referred to as a "caecal patch", which can be observed in patients with left-sided colitis 1.
Implications for Diagnosis and Treatment
- The presence of skip lesions in UC may require adjustment of medication regimens, such as increasing the dose of mesalamine to 4.8 grams per day or adding immunomodulators like azathioprine 2.5 mg/kg/day for a duration of at least 6 months to achieve adequate control of symptoms.
- Evaluation of the small bowel in addition to an ileocolonoscopy is indicated when there is macroscopic and histological rectal sparing or the presence of a caecal patch in a newly diagnosed colitis 1.
From the Research
Ulcerative Colitis and Skip Lesions
- Ulcerative colitis (UC) is typically characterized by continuous mucosal inflammation extending from the rectum to the more proximal colon, with variable extents 2, 3.
- However, some studies suggest that UC can exhibit skip lesions, which are areas of inflammation that are separated by areas of normal-appearing colon 4, 5.
- A study published in 2010 found that 10.7% of UC patients showed patchiness of disease in the colon resection specimen, with 4 of these cases being absolute 5.
- Another study published in 2018 reported a case of right-sided UC with skip lesions, which is a rare clinical type of UC that spares the anal side of the colon 4.
- It is worth noting that the presence of skip lesions in UC can make diagnosis and treatment more challenging, and may require a combination of endoscopic, histologic, and clinical evaluations to confirm the diagnosis 5.