Diagnosis and Management of Flushing

Introduction to Flushing

The American Academy of Allergy, Asthma, and Immunology recommends that anaphylaxis be ruled out immediately in any patient with acute onset flushing and diaphoresis, as it is a potentially fatal emergency that requires urgent epinephrine 1, 2, 3
The American College of Cardiology notes that anaphylaxis is highly likely if one of the following criteria is present: acute onset with cutaneous/mucosal involvement and respiratory compromise or hypotension, or involvement of two or more organ systems rapidly after allergen exposure 3
The Journal of Allergy and Clinical Immunology states that cutaneous manifestations (urticaria, angioedema, pruritus) are present in >90% of anaphylaxis cases, but their absence does not exclude the diagnosis 1
The American Heart Association recommends that epinephrine 0.3 mg be administered intramuscularly immediately if anaphylaxis is suspected, without waiting for laboratory confirmation 3

The American Academy of Allergy, Asthma, and Immunology notes that the distinctive features of vasovagal reaction include hypotension, pallor, weakness, nausea, vomiting, and diaphoresis 1, 2
The Journal of the American College of Cardiology states that bradycardia is typical of vasovagal reaction, while tachycardia characterizes anaphylaxis 1, 2, 4
The American College of Cardiology recommends that the absence of cutaneous manifestations (urticaria, angioedema, pruritus) distinguishes vasovagal reaction from anaphylaxis 1, 2

The European Society for Medical Oncology notes that carcinoid syndrome is characterized by flushing, diarrhea, lacrimation, rhinorrhea, and episodic palpitations 5
The American Thyroid Association recommends measuring serum serotonin and urinary 5-hydroxyindoleacetic acid (5-HIAA) in patients with suspected carcinoid syndrome 5, 6
The Endocrine Society states that pheochromocytoma is characterized by the "classic triad" of headache, diaphoresis, and tachycardia, but diaphoresis may be the only prominent symptom 6

The American Academy of Allergy, Asthma, and Immunology notes that pharmacological causes of flushing are much more common than neoplastic causes and must be carefully evaluated 1, 9
The American College of Cardiology recommends considering niacin, nicotinic acid, catecholamines, ACE inhibitors, and SSRIs as potential causes of flushing 1, 8, 9

The American Gastroenterological Association notes that dumping syndrome is characterized by postprandial flushing with gastrointestinal symptoms after gastric surgery 1
The American Academy of Allergy, Asthma, and Immunology states that scombroid fish poisoning is caused by histamine produced by bacteria in spoiled fish 1
The North American Menopause Society recommends considering postmenopausal flushing in women of appropriate age 1, 6

The American Academy of Allergy, Asthma, and Immunology recommends a stepwise approach to diagnosing flushing, including: