Causes of Excessive Sweating from Head to Face
Craniofacial hyperhidrosis can be either primary (idiopathic) or secondary to underlying medical conditions, medications, or systemic diseases, with secondary causes requiring systematic exclusion before diagnosing primary hyperhidrosis. 1, 2
Primary (Idiopathic) Craniofacial Hyperhidrosis
Primary hyperhidrosis affecting the head and face occurs in otherwise healthy individuals and represents focal excessive sweating without an identifiable underlying cause. 3, 4 Key diagnostic features include:
- Bilateral and symmetric sweating patterns 2
- Onset typically before age 25 years (onset after age 25 strongly suggests secondary causes with odds ratio 8.7) 2
- Absent during sleep (nocturnal sweating suggests secondary etiology with odds ratio 23.2) 2
- Episodes occurring at least weekly 2
- Duration of 6 months or more 2
- Positive family history in many cases 2
The mechanism involves abnormal central control, with the hypothalamic sweat center that controls craniofacial sweating being distinct in hyperhidrosis individuals. 5
Secondary Causes of Craniofacial Hyperhidrosis
Secondary hyperhidrosis is more likely when sweating is unilateral/asymmetric (odds ratio 51), generalized rather than focal (odds ratio 18), or present nocturnally (odds ratio 23.2). 2 Critical secondary causes include:
Endocrine Disorders
- Hyperthyroidism (Graves disease) causes increased metabolic rate, heat production, and compensatory sweating 1
- Diabetes mellitus (particularly type 2) affects thermoregulation 1
- Hypoglycemia triggers acute sweating episodes 1
- Pheochromocytoma causes episodic sweating with headache, palpitations, and pallor 6, 1
- Carcinoid syndrome 1
Neurologic Conditions
- Parkinson's disease 1
- Stroke 1
- Autonomic dysfunction 1
- Peripheral nerve injury (particularly causes asymmetric sweating with odds ratio 63 favoring neurologic disease) 2
- Spinal cord injury above T6 level can cause autonomic dysreflexia with blood pressure elevations and sweating 6
Medications and Substances
- Anticholinergic drugs affect thermoregulation 1
- Dopamine-reuptake inhibitors (ADHD medications) impair sweating regulation 1
- Oral retinoids 1
- Sympathomimetics including decongestants, cocaine, amphetamines, and ephedra cause fine tremor, tachycardia, and sweating 6
- Caffeine, nicotine, and alcohol 6
Other Medical Conditions
- Sleep apnea triggers excessive sweating 1
- Heart failure may present with diaphoresis 1
- Malignancies (lymphoma, leukemia) 1
- Fever from any infectious cause 1
- Obesity increases sweating through mechanical friction and increased pro-inflammatory cytokines 1
Critical Diagnostic Pitfalls
The most critical error is assuming all hyperhidrosis is primary without systematically excluding secondary causes, particularly thyroid dysfunction and diabetes, which are readily treatable. 1
- Always review the complete medication list for anticholinergics, stimulants, and other agents affecting thermoregulation 1
- Recent illness with fever or gastrointestinal symptoms significantly impairs thermoregulation even after apparent recovery 1
- Unilateral or asymmetric sweating mandates neurologic evaluation given the 51-fold increased odds of secondary causes 2
Recommended Diagnostic Workup
Laboratory evaluation should include: complete blood count, comprehensive metabolic panel, thyroid function tests (TSH, free T4), hemoglobin A1c, serum calcium levels, vitamin D level, and iron studies. 1 This systematic approach identifies the most common treatable secondary causes before pursuing treatment for primary hyperhidrosis.