Differential Diagnosis for Evening Flushing

The following differential diagnosis is organized into categories to help guide the thought process.

• Single most likely diagnosis

  • Carcinoid syndrome: This condition is characterized by flushing, diarrhea, wheezing, and heart valve abnormalities, often caused by a neuroendocrine tumor. The flushing in carcinoid syndrome can be triggered by certain foods, stress, or alcohol, which might explain the evening occurrence after dinner. However, the classic carcinoid syndrome typically presents with more frequent and severe symptoms.

• Other Likely diagnoses

  • Gastroesophageal reflux disease (GERD): Although not typically associated with flushing, severe GERD could potentially cause flushing due to esophageal irritation or as a vagally mediated response. The timing after dinner could correlate with lying down or eating trigger foods.
  • Menopausal hot flashes: While these are more common in women and not strictly tied to meal times, they can occur at any time, including the evening, and could potentially be triggered by the warmth or relaxation after dinner.
  • Medication side effects: Certain medications, such as niacin, can cause flushing. If the patient is taking any new medications around dinner time, this could be a plausible explanation.

• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)

  • Pheochromocytoma: A rare tumor of the adrenal gland that can cause episodic hypertension, sweating, palpitations, and flushing. Although the symptoms can be variable and not necessarily tied to meals, missing this diagnosis could be catastrophic due to the risk of hypertensive crises.
  • Thyroid storm: A life-threatening complication of untreated or undertreated hyperthyroidism. Symptoms can include flushing, fever, tachycardia, and agitation. While not typically confined to the evening, any suspicion of thyroid storm warrants immediate medical attention.

• Rare diagnoses

  • Mastocytosis: A condition characterized by the accumulation of mast cells in one or more organs. It can cause flushing, among other symptoms, due to the release of histamine and other mediators. The flushing in mastocytosis can be unpredictable but might be triggered by certain foods or stress.
  • Erythromelalgia: A disorder characterized by burning pain, heat, and redness in the hands and feet, and sometimes flushing. It can be primary or secondary to other conditions like myeloproliferative disorders. The symptoms can be intermittent and might not strictly follow a meal pattern.