Differentials
Irritable bowel syndrome (IBS)
SIGNS / SYMPTOMS
Often presents with intermittent and chronic history of diarrhoea.
INVESTIGATIONS
Clinical (no specific diagnostic test for IBS). Urinary 5-hydroxyindoleacetic acid (5-HIAA) and chromogranin A will be normal.
Crohn's disease
SIGNS / SYMPTOMS
Right lower quadrant pain and peri-anal lesions. May also present with oral lesions.
INVESTIGATIONS
Urinary 5-HIAA and chromogranin A will be normal.
Inflammatory markers such as CRP and faecal calprotectin may be raised.
Ileocolonoscopy: aphthous ulcers, hyperaemia, oedema, cobblestoning, skip lesions.
Menopause
SIGNS / SYMPTOMS
Amenorrhoea or irregular menstrual cycle; vaginal dryness, itching, and dyspareunia; pale, dry vaginal mucosa with decreased rugosity; mood changes.
INVESTIGATIONS
Gonadotrophins (LH/FSH) will be raised.
Asthma
SIGNS / SYMPTOMS
If wheeze is the only symptom of myxoma carcinoid, then it may be mistaken for asthma. Absence of diarrhoea and abdominal pain.
INVESTIGATIONS
Spirometry (FEV₁/FVC ratio) positive for airflow obstruction.
Mast cell activation syndrome
SIGNS / SYMPTOMS
Typical symptoms are similar to those that can occur in carcinoid syndrome, including flushing, diarrhoea, palpitations, tachycardia, abdominal pain and severe hypotension.
INVESTIGATIONS
Serum tryptase raised.
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