Causes of Facial Flushing
Facial flushing can be caused by numerous conditions ranging from benign to potentially life-threatening, with the most common causes being rosacea, medication reactions, emotional responses, and certain systemic diseases. 1, 2
Common Causes
Physiological Causes
- Emotional responses: Embarrassment, anxiety, stress, or excitement 3
- Temperature changes: Exposure to heat, hot beverages, spicy foods
- Exercise-induced flushing
- Alcohol consumption: Causes vasodilation and can trigger facial flushing 4
Dermatological Conditions
- Rosacea: Characterized by persistent centrofacial erythema, telangiectasia, inflammatory papules/pustules, and phymatous changes 5
- More common in fair-skinned individuals but can occur in all skin types
- Often presents with history of easy facial flushing
- May be challenging to diagnose in darker skin tones
Medication-Related Causes
- Vasodilating drugs: Niacin, calcium channel blockers, nitroglycerin
- Other medications:
- Antidepressants
- Anticholinergics
- Angiotensin-converting enzyme inhibitors
- Systemic retinoids (e.g., isotretinoin)
- Diuretics 1
- Alcohol interaction with medications: Metronidazole can cause flushing when combined with alcohol 4
Endocrine and Neoplastic Causes
- Carcinoid syndrome: Characterized by episodic flushing, diarrhea, and wheezing 6, 2
- Pheochromocytoma: Presents with paroxysmal hypertension, headaches, and flushing 6
- Mastocytosis: Abnormal mast cell proliferation causing flushing and other symptoms 7
- Menopausal hot flushes: Due to estrogen deficiency affecting hypothalamic temperature regulation 8
- Other rare causes: Medullary thyroid cancer, VIPoma, renal cell carcinoma 6, 2
Allergic and Immunologic Reactions
- Anaphylaxis: Life-threatening reaction with flushing, urticaria, angioedema, and respiratory/cardiovascular symptoms 1
- Food reactions: Including scombroid fish poisoning (histamine toxicity from spoiled fish) 1
- Mast cell activation syndrome: Characterized by recurrent flushing episodes and mast cell mediator release 6
Diagnostic Approach
Key Clinical Features to Assess
- Pattern and distribution: Centrofacial (typical for rosacea) vs. generalized
- Timing: Transient vs. persistent, relationship to triggers
- Associated symptoms: Presence of sweating, palpitations, diarrhea, wheezing, or hypotension
- Triggers: Foods, medications, alcohol, emotional stimuli, temperature changes
Laboratory Investigations (Based on Clinical Suspicion)
- For suspected anaphylaxis: Serum tryptase (ideally 1-2 hours after onset) 1
- For suspected carcinoid: 24-hour urinary 5-hydroxyindoleacetic acid
- For suspected pheochromocytoma: Plasma-free metanephrine, urinary vanillylmandelic acid 1
- For suspected mastocytosis: Serum tryptase, skin biopsy
Management Considerations
Management depends on identifying and addressing the underlying cause:
- Rosacea: Avoidance of triggers, topical treatments (metronidazole), oral antibiotics, laser therapy 5
- Medication-induced: Discontinuation or adjustment of causative medications
- Menopausal flushing: Hormone replacement therapy if appropriate, non-hormonal alternatives like selective serotonin reuptake inhibitors 8
- Carcinoid syndrome: Somatostatin analogs, surgical resection of tumor
- Anxiety-related flushing: May respond to anxiolytics or antidepressants like venlafaxine 3
Important Pitfalls to Avoid
- Missing serious underlying conditions: Always consider carcinoid syndrome, pheochromocytoma, and mastocytosis in recurrent unexplained flushing
- Attributing all facial flushing to rosacea: Especially when accompanied by systemic symptoms
- Overlooking medication causes: Always review complete medication list, including over-the-counter drugs
- Failing to recognize anaphylaxis: Flushing with respiratory symptoms or hypotension requires immediate treatment
- Dismissing emotional causes: Anxiety can be a significant trigger for facial flushing but should be a diagnosis of exclusion 6, 3
When evaluating facial flushing, a systematic approach focusing on pattern, triggers, and associated symptoms will guide appropriate diagnostic testing and management strategies to address both the symptom and its underlying cause.