Could This Be Histamine Intolerance?
Your symptoms of rhinorrhea, hot arms, and low-grade fever shortly after eating that resolve at night are unlikely to represent histamine intolerance and should prompt investigation for other causes, particularly given your history of Crohn's disease and SIBO.
Why This Is Unlikely to Be Histamine Intolerance
Symptom Pattern Mismatch
Fever is not a recognized manifestation of histamine intolerance. The established symptoms include headache, diarrhea, flushing, urticaria, asthma-like symptoms, rhinitis, hypotension, arrhythmia, and pruritus—but not fever 1, 2, 3.
The temporal pattern you describe (symptoms resolving at night) is atypical. Histamine intolerance symptoms typically occur within minutes to hours after ingesting histamine-rich foods and persist until histamine is metabolized, not following a diurnal pattern 2, 4.
"Hot arms" is not a documented symptom of histamine intolerance. While flushing (generalized redness and warmth) can occur, isolated warmth in specific body regions is not characteristic 1, 5, 2.
Diagnostic Challenges
Histamine intolerance diagnosis requires systematic exclusion of other disorders with similar symptoms and confirmation through response to a low-histamine diet, which is considered the gold standard 1, 4.
The diagnosis is notoriously difficult because symptoms are non-specific and variable, often mimicking allergies, food intolerance, mastocytosis, and other conditions 3, 4.
Available tests for diamine oxidase (DAO) deficiency have questionable informative value, making clinical response to dietary modification the most reliable diagnostic criterion 4.
More Likely Explanations in Your Context
SIBO-Related Manifestations
Your known SIBO can cause post-prandial symptoms including bloating, abdominal discomfort, and flatulence that characteristically worsen after eating 6.
SIBO symptoms overlap significantly with other functional bowel disorders, making clinical distinction challenging 6.
Patients with Crohn's disease and SIBO are at increased risk for recurrent bacterial overgrowth, occurring in up to 14% of patients even after successful treatment 7.
Crohn's Disease Activity
Low-grade fever can indicate active inflammatory bowel disease, which would be more consistent with your Crohn's history than histamine intolerance 8.
Post-prandial symptoms are common in Crohn's disease due to intestinal inflammation and altered motility 9.
Elevated inflammatory markers (fecal calprotectin, lactoferrin) would support active Crohn's disease rather than SIBO or histamine intolerance, as SIBO does not elevate these markers 8.
Recommended Diagnostic Approach
Immediate Evaluation
Check fecal calprotectin levels. Elevated levels (>50-60 mg/g) have 81% sensitivity and 87% specificity for detecting organic inflammation in IBD, which would suggest active Crohn's disease rather than functional symptoms 8.
Assess for SIBO recurrence using hydrogen and methane breath testing with glucose or lactulose, which is more accurate than hydrogen-only testing 7.
Document fever objectively with temperature measurements to confirm it is truly present and not subjective warmth 9.
Rule Out Other Causes
Consider food protein-induced enterocolitis syndrome (FPIES) if vomiting occurs 1-4 hours after eating, though this typically presents with more severe symptoms including lethargy, pallor, and hypotension 9.
Evaluate for IgE-mediated food allergy if symptoms include respiratory compromise or urticaria, though your symptom pattern is atypical for this 9.
Investigate for bile acid diarrhea or pancreatic exocrine insufficiency if symptoms persist after SIBO treatment, as these conditions commonly coexist 7.
Clinical Pitfalls to Avoid
Do not attribute fever to histamine intolerance, as this is not a recognized manifestation and may delay diagnosis of inflammatory conditions 1, 2.
Do not empirically trial a low-histamine diet without first excluding active Crohn's disease, as untreated inflammation can lead to complications 8.
Do not assume SIBO is adequately treated without confirmatory breath testing, as symptoms may persist from other causes 7.
Recognize that proton pump inhibitor use (if applicable) is a well-established risk factor for SIBO development and should be discontinued if possible 7.