What could be causing a metallic taste in the mouth with right‑sided abdominal pain, and what evaluation and management are recommended?

Metallic Taste with Right-Sided Abdominal Pain: Evaluation and Management

Immediate Diagnostic Approach

The combination of metallic taste and right-sided abdominal pain requires urgent imaging with CT abdomen and pelvis with IV contrast to evaluate for biliary pathology, hepatobiliary disease, and other intra-abdominal emergencies, while recognizing that metallic taste may indicate medication effect (particularly metronidazole), copper toxicity from a foreign body, or systemic illness associated with the underlying abdominal pathology. 1, 2

Critical Initial Assessment

The right-sided abdominal pain localizes the differential diagnosis and requires specific evaluation:

• Right upper quadrant pain with fever and Murphy's sign suggests acute cholecystitis, which is the most common biliary emergency requiring imaging 1
• Right lower quadrant pain with fever raises concern for appendicitis, though other diagnoses including right-sided diverticulitis must be considered 1
• Right-sided pain in critically ill patients on vasopressors should raise suspicion for non-occlusive mesenteric ischemia (NOMI), which can present with right-sided abdominal pain and carries high mortality 1

Imaging Strategy

Ultrasound is the investigation of choice for suspected acute cholecystitis, looking for pericholecystic fluid, distended gallbladder, edematous gallbladder wall, and gallstones impacted in the cystic duct 1

CT abdomen and pelvis with IV contrast should be obtained when:

• Ultrasound is negative or inconclusive 1, 3
• Clinical presentation is atypical or non-localized 1, 3
• There is concern for alternative diagnoses including appendicitis, diverticulitis, perforation, or mesenteric ischemia 1

CT has 95% sensitivity and 94% specificity for appendicitis and identifies alternative diagnoses in 94.3% of cases with non-appendiceal pathology 1

Understanding the Metallic Taste Component

Medication-Related Causes

Metronidazole is the most common medication causing metallic taste and should be reviewed in any patient's medication list. The FDA label specifically lists "a sharp metallic taste" and "an unpleasant metallic taste" as common adverse reactions 2

Other medications and chemotherapy agents can also cause metallic taste, with an estimated prevalence of 29% in cancer patients 4

Foreign Body Consideration

A rare but documented cause of metallic taste is a copper-containing foreign body in the gastric wall, which can be detected by MRI and confirmed by elevated serum copper levels 5

While uncommon, unnoticed swallowed foreign bodies (including toothpicks) can cause right-sided abdominal pain and may be misdiagnosed as appendicitis 6

Systemic Illness Association

Metallic taste may be a non-specific symptom accompanying serious intra-abdominal pathology, particularly in the setting of:

• Severe infection or sepsis 1
• Hepatobiliary dysfunction 1
• Gastrointestinal bleeding or ischemia 1

Specific Clinical Scenarios and Management

Right Upper Quadrant Pain with Metallic Taste

For uncomplicated cholecystitis: Early laparoscopic cholecystectomy within 7-10 days of symptom onset with one-shot antibiotic prophylaxis and no post-operative antibiotics 1

For complicated cholecystitis in immunocompetent, non-critically ill patients:

• Laparoscopic cholecystectomy with antibiotic therapy for 4 days if source control is adequate 1
• Amoxicillin/clavulanate 2g/0.2g q8h is first-line antibiotic therapy 1

For critically ill or immunocompromised patients:

• Piperacillin/tazobactam 6g/0.75g loading dose then 4g/0.5g q6h or 16g/2g by continuous infusion 1
• Antibiotic therapy up to 7 days based on clinical conditions if source control is adequate 1

Right Lower Quadrant Pain with Metallic Taste

CT abdomen and pelvis with IV contrast is the preferred initial imaging with 95% sensitivity for appendicitis 1

For uncomplicated appendicitis:

• Laparoscopic appendectomy with antibiotic therapy until intervention and 2-4 subsequent days 1
• Antibiotic therapy for 2-4 days in immunocompetent, non-critically ill patients if source control is adequate 1

Critical Illness Considerations

In critically ill patients on vasopressor support with right-sided abdominal pain, suspect NOMI, which presents with:

• Unexplained abdominal distension or gastrointestinal bleeding 1
• Right-sided abdominal pain with passage of maroon or bright red blood 1
• New onset organ failure or increased vasoactive support requirements 1

CTA may demonstrate bowel ischemia with patent mesenteric vessels in NOMI 1

Laboratory Evaluation

Obtain the following tests concurrently with imaging:

• Complete blood count to assess for leukocytosis indicating infection 3
• Comprehensive metabolic panel including liver function tests (ALT, AST, alkaline phosphatase, bilirubin) 3
• Serum lipase for suspected pancreatitis 3
• Beta-hCG in all women of reproductive age before CT 3
• Consider serum copper level if foreign body suspected based on history 5

Critical Pitfalls to Avoid

Do not dismiss right-sided abdominal pain as benign without imaging when clinical suspicion exists, as CT alters diagnosis in nearly half of cases 3

Do not attribute metallic taste solely to medication without evaluating the abdominal pathology, as serious conditions may coexist 2, 5

In critically ill patients, do not delay imaging for suspected NOMI, as approximately 25% of cases may be undetectable on clinical examination in sedated ICU patients 1

Vasopressors should be used with caution in patients with suspected mesenteric ischemia, as norepinephrine and epinephrine may worsen mucosal perfusion 1

Immediate Resuscitation Measures

When diagnosis of acute intra-abdominal infection is made, commence fluid resuscitation immediately with crystalloid and blood products to enhance visceral perfusion 1

Correct electrolyte abnormalities and initiate nasogastric decompression, particularly important in patients with bowel infarction who may develop severe metabolic acidosis and hyperkalemia 1

Implement early hemodynamic monitoring to guide effective resuscitation and prevent cardiovascular collapse on induction of anesthesia 1