A 52-year-old woman is evaluated for a 1-year history of diarrhea. The patient describes "runs" of watery diarrhea that last several weeks before subsiding but then reappear. She has been taking over-the-counter loperamide and bismuth subsalicylate, which provide only transient symptom relief. The patient has also experienced a 5-kg (11-lb) weight loss over the past year but has had no fever, abdominal pain, or rectal bleeding. Medical history is notable for hypertension and depression treated with ramipril and fluoxetine, respectively. She is an ex-smoker with a 12-pack-year history and does not drink alcohol.
Vital signs are normal. Examination reveals mild, generalized abdominal tenderness with no guarding or rebound tenderness. Bowel sounds are normal. Test for stool occult blood is negative.
Blood cell counts, serum chemistry studies, and TSH levels are within normal limits. HIV and stool tests for infection are negative. IgA anti-tissue transglutaminase antibodies are negative with normal IgA levels. Colonoscopy reveals grossly normal terminal ileal and colonic mucosa. Random biopsies show a lymphocyte-predominant mononuclear infiltrate with few neutrophils and eosinophils in the lamina propria. Crypt architecture is preserved, but focal cryptitis is present.
Which of the following is most appropriate next step in management of this patient's illness?

Question

A 52-year-old woman is evaluated for a 1-year history of diarrhea.  The patient describes "runs" of watery diarrhea that last several weeks before subsiding but then reappear.  She has been taking over-the-counter loperamide and bismuth subsalicylate, which provide only transient symptom relief.  The patient has also experienced a 5-kg (11-lb) weight loss over the past year but has had no fever, abdominal pain, or rectal bleeding.  Medical history is notable for hypertension and depression treated with ramipril and fluoxetine, respectively.  She is an ex-smoker with a 12-pack-year history and does not drink alcohol.
Vital signs are normal.  Examination reveals mild, generalized abdominal tenderness with no guarding or rebound tenderness.  Bowel sounds are normal.  Test for stool occult blood is negative.
Blood cell counts, serum chemistry studies, and TSH levels are within normal limits.  HIV and stool tests for infection are negative.  IgA anti-tissue transglutaminase antibodies are negative with normal IgA levels.  Colonoscopy reveals grossly normal terminal ileal and colonic mucosa.  Random biopsies show a lymphocyte-predominant mononuclear infiltrate with few neutrophils and eosinophils in the lamina propria.  Crypt architecture is preserved, but focal cryptitis is present.
Which of the following is most appropriate next step in management of this patient's illness?

Quizplus · Accepted Answer

11ec193a_97fe_0f59_853d_43a00a274be3_MD0002_00 This patient has microscopic colitis (MC), a type of inflammatory bowel disease that disproportionately affects middle-aged women. MC is likely due to an abnormal immune response to various gastrointestinal and external agents, including certain medications (eg, nonsteroidal anti-inflammatory drugs, proton pump inhibitors, sertraline) and smoking. It can be associated with other autoimmune diseases (eg, type 1 diabetes, thyroiditis). MC presents with chronic watery, nonbloody diarrhea, often with fatigue, weight loss, abdominal pain, arthralgias, or uveitis. The colon appears grossly normal by colonoscopy, but biopsy of the mucosa reveals mononuclear lymphocytic infiltrates in the lamina propria. MC is subdivided histologically into 2 types: Collagenous colitis - characterized by a thickened subepithelial collagen bandLymphocytic colitis - characterized by high levels of intraepithelial lymphocytes (≥20 for every 100 epithelial cells); focal cryptitis may occur Collagenous colitis - characterized by a thickened subepithelial collagen band Collagenous colitis - characterized by a thickened subepithelial collagen band Lymphocytic colitis - characterized by high levels of intraepithelial lymphocytes (≥20 for every 100 epithelial cells); focal cryptitis may occur Lymphocytic colitis - characterized by high levels of intraepithelial lymphocytes (≥20 for every 100 epithelial cells); focal cryptitis may occur Initial treatment includes antidiarrheal agents and withdrawal of possible triggering medications. Oral budesonide may be added for active disease or persistent symptoms. Other options for refractory disease include cholestyramine, bismuth subsalicylate, and tumor necrosis factor inhibitors (eg, infliximab, adalimumab). (Choice A) Tricyclic antidepressants (eg, amitriptyline) are used for moderate to severe irritable bowel syndrome. Irritable bowel syndrome causes chronic abdominal pain and altered bowel habits but would not typically cause weight loss, progressive symptoms, or abnormalities on biopsy. (Choice B) A gluten-free diet is the therapy of choice for celiac disease, which can manifest as lymphocytic colitis on biopsy; however, this patient has normal IgA levels and absent tissue transglutaminase antibodies, virtually ruling out this disease. (Choices C and D) Hydrocortisone suppositories and mesalamine enemas are commonly used in left-sided ulcerative colitis, which is characterized by recurrent episodes of inflammation that are limited to the mucosal layer. Patients typically have bloody diarrhea. Oral mesalamine is sometimes used as a second-line agent in patients with lymphocytic colitis who cannot receive budesonide; however, the benefits are not clear. Educational objective: Microscopic colitis presents as chronic watery diarrhea without bleeding. Colonoscopy reveals a grossly normal mucosa with mononuclear lymphocytic infiltrates on biopsy. Initial management includes antidiarrheal medications and discontinuation of causative drugs. Budesonide can be added for persistent symptoms. __________ References: Prednisolone and budesonide for short- and long-term treatment of microscopic colitis: systematic review and meta-analysis. (http://www.ncbi.nlm.nih.gov/pubmed/21699817) Microscopic colitis: a concise review. (http://www.ncbi.nlm.nih.gov/pubmed/20931164)

A 52-Year-Old Woman Is Evaluated for a 1-Year History of Diarrhea