Differential Diagnosis of Hot Flashes

Case

In clinic there was an interesting case of a 72 F who experienced severe and debilitating hot flashes triggered by cold water, direct sunlight and some neck movements. This would be followed by multiple hours of chills. She had extensive work up by her GP, endocrinologist and psychiatrist before being referred to the GIM clinic. Differential diagnosis of hot flashes/flushing are presented below.

Differential Diagnosis

Autonomic Mediated 

• thermoregulatory (fever, exercise, heat exposure)
• menopause
• emotional 
• neurologic (masses that compress the third ventricle, diencephalic autonomic epilepsy, cluster headache, spinal cord injury, Parkinson's disease, multiple sclerosis, autonomic hyperreflexia, Frey syndrome, trigeminal neuralgia, migraine, Harlequin syndrome)

Vasodilation Mediated

• rosacea
• medications
• food (spicy, MSG, alcohol)
• carcinoid syndrome
• mastocytosis
• pheochromocytoma
• Medullary thyroid carcinoma
• Serotonin syndrome
• Anaphylaxis
• Pancreatic tumour/VIPoma
• Dumping syndrome or short-gut syndrome
• Sarcoidosis 
• Hyperthyroidism
• Bronchogenic carcinoma
• Androgen deficiency
• Renal cell carcinoma
• Superior vena cava syndrome 

In this patient specifically, post-menopausal vasomotor symptoms were considered. She had a hysterectomy at age 42 and received hormone replacement therapy for 5 years. Her symptoms began around age 60. According to the SWAN study, the median total vasomotor symptom duration is 7.4 years. However our patient has risk factors for longer duration including African ethnicity and psychiatric comorbidity. Furthermore, the DREAMS study which looked at menopausal women >60 years found that those with moderate-severe vasomotor symptoms were more likely to have non-spontaneous menopause. However, symptoms caused by menopause are generally expected to improve with time and not worsen. Therefore additional investigations for rarer causes of flushing were pursued.

References

https://www-uptodate-com.myaccess.library.utoronto.ca/contents/approach-to-flushing-in-adults?search=hot%20flash&source=search_result&selectedTitle=11~150&usage_type=default&display_rank=11

https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2110996

https://pubmed.ncbi.nlm.nih.gov/29738420/

A.L.