Review Question - QID 212891

This patient has carcinoid syndrome as characterized by flushing, diarrhea, and pellagra (e.g., diarrhea, dementia, sores, and skin changes). The most appropriate treatment for carcinoid syndrome is octreotide.

Carcinoid syndrome refers to the paraneoplastic syndrome that occurs secondary to carcinoid tumors, which are well-differentiated neuroendocrine tumors that originate in the digestive tract, lungs, or rarely, the kidneys or ovaries. It is a result of the endogenous secretion of serotonin and to a lesser extent, kallikrein. Carcinoid syndrome generally does not occur when the tumor is localized at the digestive tract as the hepatic portal circulation metabolizes the released serotonin. The most common clinical presentation includes flushing and diarrhea. Pellagra can also occur due to the overproduction of serotonin, which depletes the body’s niacin store. Symptomatic relief of the syndrome can be accomplished via octreotide, which is a somatostatin analog that decreases the secretion of serotonin.

Figure A is a clinical image demonstrating inflammatory skin changes (e.g., erythematous patches with skin peeling) characteristic of pellagra.

Incorrect Answers:
Answer 1: Corticosteroids are an anti-inflammatory treatment for various diseases. They can be used for acute exacerbations of Crohn disease, which can present with diarrhea and abdominal pain. However, this patient’s flushing and pellagra suggest carcinoid syndrome.

Answer 2: Infliximab is a monoclonal antibody against tumor necrosis factor-alpha and can be used in the treatment of inflammatory bowel disease.

Answer 3: Loperamide is an agonist at mu-opioid receptors. It is used for its ability to slow the gut and therefore provide anti-diarrheal effects. Although this may provide temporary symptomatic relief, it does not address the ultimate cause of this patient’s symptoms.

Answer 5: Zidovudine is a nucleoside reverse-transcriptase inhibitor (NRTI) used in the treatment of human immunodeficiency virus (HIV). Although HIV can present with diarrhea, sores, and dementia, this patient’s other symptoms (e.g., flushing) suggest carcinoid syndrome. In addition, NRTIs are never to be used as monotherapy and should be combined with other medications to prevent resistance.

Bullet Summary:
Carcinoid syndrome can be symptomatically treated with octreotide.