Episodic diurnal diaphoresis

Specialty: General.

• intermittent profuse daytime sweating
• daytime sweating attack
• episodic excessive sweating

Why it occurs

• Reactive or fasting hypoglycemic crisis (massive sympathetic discharge with release of adrenaline to stimulate hepatic gluconeogenesis)
• Crisis of pheochromocytoma or neuroendocrine tumors (massive episodic secretion of catecholamines or vasoactive peptides)
• Climacteric or menopausal flushing syndrome (hypothalamic thermoregulatory dysfunction due to estrogen deprivation)
• Panic attacks or severe anxiety attacks (reflex activation of the sympathetic nervous system with stimulation of the eccrine sweat glands)
• Adverse reactions or plasma peaks of certain medications (SSRI antidepressants, beta blockers, oral hypoglycemic agents or opioid analgesics).

Initial workup

Determination of free fractionated metanephrines in plasma or 24-hour urine (to rule out pheochromocytoma), capillary glucose or continuous glucose monitoring during episodes, thyroid profile, and FSH and estradiol levels in women.

Standard management

• Clonidine — 0.075 to 0.1 mg orally every 12 hours if sympathetic hyperactivity is confirmed as the cause of the vasomotor condition
• Propranolol — 10 to 20 mg orally twice daily to mitigate peripheral adrenergic effects such as sweating and tachycardia
• Gabapentin (100 to 300 mg orally at night, useful to reduce episodes of refractory climacteric vasomotor sweating).