81: Hyperhydrosis and Anhidrosis

Question 1

What is hyperhidrosis and how does it differ from anhidrosis?

Answer 1

Hyperhidrosis is excessive sweating beyond what is physiologically necessary to maintain normal body temperature, while anhidrosis is the inability to generate sweat when it is physiologically necessary to dissipate heat, which can lead to medical emergencies like hyperthermia or heat stroke.

Question 2

What are the clinical features of primary focal hyperhidrosis?

Answer 2

The clinical features of primary focal hyperhidrosis include:
- Excessive sweating at baseline in various anatomical locations (palms, soles, axillae, craniofacial region, groin).
- Affects both males and females equally.
- Begins in childhood (palmar-plantar) or during puberty (axillary).
- Persists into adulthood and rarely improves spontaneously.
- Severity ranges from mild (moist skin) to severe (dripping wet).

Question 3

What are the diagnostic criteria for hyperhidrosis?

Answer 3

The diagnostic criteria for hyperhidrosis include:
- Focal visible excessive sweating for ≥6 months without apparent cause.
- At least two of the following:
- Bilateral and relatively symmetric sweating.
- Age of onset typically before age 25 years.
- Cessation of sweating from the focal areas during sleep.
- Frequency of at least once per week.
- Positive family history.
- Sweating impairs daily activities.

Question 4

What triggers hyperhidrosis?

Answer 4

Triggers for hyperhidrosis include:
- Increased temperature.
- Anxiety.
- Stress.
- Physical activity.

Question 5

What are the first-line treatment options for hyperhidrosis?

Answer 5

First-line treatment options for hyperhidrosis include:
- Over-the-counter antiperspirants.
- Aluminum chloride hexahydrate (10% to 35%), which is best applied to dry skin at bedtime and washed off after 6 to 8 hours.

If moisture is present when applied, it can form a weak hydrochloric acid, causing burning, irritation, or desquamation.

Question 6

What is the most likely diagnosis for a patient with excessive sweating on their palms and soles that worsens during stress?

Answer 6

The most likely diagnosis is Primary Focal Hyperhidrosis. Diagnostic criteria include focal visible excessive sweating for ≥6 months without apparent cause and at least two of the following: bilateral and symmetric sweating, onset before age 25, cessation during sleep, frequency of at least once per week, positive family history, and impairment of daily activities.

Question 7

What is the next step in treatment for severe axillary sweating that has not responded to over-the-counter antiperspirants?

Answer 7

The next step is the application of aluminum chloride hexahydrate (10%-35%), which is best applied to dry skin at bedtime and washed off after 6-8 hours. It works by forming a weak hydrochloric acid that blocks sweat ducts.

Question 8

What are the key diagnostic criteria for focal visible excessive sweating classified as hyperhidrosis?

Answer 8

The diagnostic criteria for hyperhidrosis include:
- Focal visible excessive sweating for ≥6 months without apparent cause
- At least two of the following:
- Bilateral and relatively symmetric sweating
- Age of onset typically before age 25
- Cessation of sweating from the focal areas during sleep
- Frequency of at least once per week
- Positive family history
- Sweating impairs daily activities.

Question 9

What are the common triggers for primary hyperhidrosis?

Answer 9

Common triggers for primary hyperhidrosis include:
- Increased temperature
- Anxiety
- Stress
- Physical activity.

Question 10

What are the clinical features of primary focal hyperhidrosis?

Answer 10

Clinical features of primary focal hyperhidrosis include:
- Excessive sweating at baseline in various anatomic locations (palms, soles, axillae, craniofacial region, groin)
- Affects both males and females equally
- Begins in childhood (palmar-plantar) or during puberty (axillary)
- Persists into adulthood
- Ranges from mild (moist skin) to severe (dripping wet) excessive sweating.

Question 11

What is the first-line therapy for managing hyperhidrosis?

Answer 11

The first-line therapy for managing hyperhidrosis includes:
- Over-the-counter antiperspirants
- Aluminum chloride hexahydrate (10% to 35%)

Application Instructions:
- Best applied to dry skin at bedtime
- Washed off after 6 to 8 hours
- Caution: If moisture is present during application, it can lead to burning, irritation, or desquamation due to hydrochloric acid formation.

Question 12

What are the potential medical complications associated with primary hyperhidrosis?

Answer 12

Potential medical complications associated with primary hyperhidrosis include:
- Maceration
- Secondary infections
- Pitted keratolysis
- Dermatophytosis
- Verruca vulgaris or plantaris.

Question 13

What is the mechanism of action of Botulinum Toxin in treating hyperhidrosis?

Answer 13

Botulinum Toxin acts on the cholinergic synapses by inhibiting acetylcholine release, which helps reduce sweating in the treated areas.

Question 14

What are the side effects associated with Glycopyrrolate when used for hyperhidrosis?

Answer 14

Side effects of Glycopyrrolate include:
- Erythema
- Mild pain or discomfort
- Paresthesia in the treatment zone.

Question 15

What is the purpose of Endoscopic Thoracic Sympathectomy (ETS) in hyperhidrosis treatment?

Answer 15

ETS is used for severe cases of palmar hyperhidrosis that have failed conservative management. It can lead to complications such as compensatory sweating in other body segments and other serious risks.

Question 16

What is the FDA-approved use of miraDry in hyperhidrosis treatment?

Answer 16

miraDry is an FDA-approved procedure for adults with primary axillary hyperhidrosis. It uses microwave energy to permanently destroy eccrine glands, reducing sweating in the treated area.

Question 17

What is the recommended maintenance frequency for Tap Water Iontophoresis Therapy after initial treatments?

Answer 17

After initial treatments, Tap Water Iontophoresis Therapy typically requires maintenance treatments 1-2 times per week to sustain its effects.

Question 18

What are the contraindications for using oral anticholinergic agents like Glycopyrrolate and Clonidine?

Answer 18

Oral anticholinergic agents are contraindicated in:
- Myasthenia gravis
- Paralytic ileus
- Pyloric stenosis
Caution is also advised in patients with closed-angle glaucoma, bladder outflow obstruction, gastroesophageal reflux disease, and cardiac insufficiency.

Question 19

What is the mechanism of action of topical glycopyrrolate in treating craniofacial hyperhidrosis?

Answer 19

Topical glycopyrrolate is an anticholinergic agent that inhibits acetylcholine at muscarinic receptors, reducing sweat production.

Question 20

What surgical option is available for a patient with severe palmar hyperhidrosis who has failed conservative management?

Answer 20

Endoscopic Thoracic Sympathectomy (ETS) is an option. Potential complications include compensatory sweating, Horner syndrome, bradycardia, pneumothorax, pleural effusion, acute bleeding, delayed hemothorax, chylothorax, and persistent intercostal neuralgia.

Question 21

What is the duration of efficacy for botulinum toxin injections in axillary hyperhidrosis?

Answer 21

The median duration of efficacy is 4-5 months. Off-label areas include the face, scalp, palms, soles, inframammary folds, and inguinal folds.

Question 22

What is the rationale for using propranolol in managing stress-induced hyperhidrosis?

Answer 22

Propranolol, a beta-blocker, is effective in managing stress-induced hyperhidrosis by reducing the physiological effects of stress on sweat production.

Question 23

What are the clinical implications of using Botulinum Toxin for treating hyperhidrosis?

Answer 23

Botulinum Toxin acts on the cholinergic synapses by inhibiting acetylcholine release, which reduces sweating. It is effective for patients who do not respond to topical therapies and has a median duration of effect of 4 to 5 months. It is FDA-approved for severe primary axillary hyperhidrosis in adults 18 years and older, and can also be used off-label for other focal areas such as the face, scalp, and palms.

Question 24

What are the potential complications associated with Endoscopic Thoracic Sympathectomy (ETS) for palmar hyperhidrosis?

Answer 24

Complications of ETS include:
1. Increased risk of compensatory sweating in body segments below the treated area.
2. Less common complications such as Horner syndrome, bradycardia, and pneumothorax requiring chest tube drainage.
3. Other risks include pleural effusion, acute bleeding, delayed hemothorax, chylothorax, and persistent intercostal neuralgia.

Question 25

How does Glycopyrrolate function as an anticholinergic agent in the treatment of hyperhidrosis?

Answer 25

Glycopyrrolate is an anticholinergic that can be crushed and mixed with water to enhance sweat reduction. It works by limiting the passage across lipid membranes, which helps reduce sweating. Side effects include: - Erythema - Mild pain or discomfort - Paresthesia in the treatment zone.

Question 26

What is the mechanism of action and contraindications for using oral anticholinergic agents like oxybutynin and clonidine in hyperhidrosis treatment?

Answer 26

Oral anticholinergic agents like oxybutynin and clonidine work by blocking cholinergic receptors, thus reducing sweating. However, they are contraindicated in conditions such as: - Myasthenia gravis - Paralytic ileus - Pyloric stenosis Caution is advised in patients with closed-angle glaucoma, bladder outflow obstruction, and cardiac insufficiency due to potential side effects like xerostomia, constipation, and bradycardia.

Question 27

What are the primary causes of secondary hyperhidrosis?

Answer 27

Secondary hyperhidrosis can occur due to: 1. Endocrine diseases (57% of cases) - including diabetes mellitus, hyperthyroidism, and hyperpituitarism. 2. Neurologic diseases (32% of cases) - presenting as asymmetric hyperhidrosis. 3. Malignancies - such as pheochromocytoma. 4. Respiratory diseases and psychiatric diseases. 5. Physiologic or pathologic gustatory sweating and other neurologic dysfunctions.

Question 28

What is Frey syndrome and what are its causes?

Answer 28

Frey syndrome is characterized by localized sweating on the lips, forehead, scalp, and nose while eating hot and spicy foods. It can occur due to: - Injury or surgery in the region of the parotid gland, leading to aberrant regeneration of autonomic fibers of the auriculotemporal nerve. - Birth trauma in infants and children, particularly with forceps delivery. - Upper thoracic and cervical sympathectomy, facial herpes zoster, or chorda tympani injury. - It may also be associated with cluster headaches and diabetes mellitus.

Question 29

What are the clinical features of generalized secondary hyperhidrosis?

Answer 29

The clinical features of generalized secondary hyperhidrosis include: - Focal, regional, or generalized sweating that often persists during sleep. - Onset typically occurs in adulthood. - Can result from various underlying conditions such as metabolic disorders, infections, malignancies, or as a side effect of medications or toxins.

Question 30

What is paroxysmal localized hyperhidrosis and its treatment options?

Answer 30

Paroxysmal localized hyperhidrosis is characterized by episodes of excessive sweating affecting the head, neck, and upper trunk. It is more common in older postmenopausal women and less commonly in men. Treatment options include: - Clonidine - Topical or oral glycopyrrolate Hormonal replacement therapy is generally ineffective for this condition.

Question 31

What is eccrine nevus and how is it treated?

Answer 31

Eccrine nevus is a rare skin hamartoma defined histologically as focal hyperplasia or hypertrophy of eccrine glands. It is characterized by: - A hyperhidrotic isolated patch of skin with no epidermal changes. - Frequently located on the forearm. ## Footnote **Treatment** depends on the severity and may include: - Botulinum toxin injections - Topical glycopyrrolate.

Question 32

What is the likely cause of asymmetric hyperhidrosis in a patient with a history of brainstem stroke?

Answer 32

The likely cause is secondary hyperhidrosis due to neurologic disease, such as a brainstem stroke, which can disrupt autonomic regulation.

Question 33

What is gustatory sweating and what triggers it?

Answer 33

Gustatory sweating is a physiological response via the trigeminovascular reflex triggered by hot and spicy foods.

Question 34

What is the diagnosis for localized sweating on the cheek after parotid gland surgery?

Answer 34

The diagnosis is Frey syndrome, caused by aberrant regeneration of autonomic fibers after trauma to the auriculotemporal nerve.

Question 35

What is the likely cause of paroxysmal hyperhidrosis in a postmenopausal woman, and what treatment options are available?

Answer 35

The likely cause is alterations in the hypothalamic set point temperature range for sweating. Treatment options include clonidine or topical/oral glycopyrrolate.

Question 36

What are the primary causes of secondary hyperhidrosis and how do they differ between localized and generalized forms?

Answer 36

Primary causes of secondary hyperhidrosis: 1. Endocrine diseases (57% of cases): Includes conditions like diabetes mellitus, hyperthyroidism, and hyperpituitarism. 2. Neurologic diseases (32% of cases): Can present as asymmetric hyperhidrosis. 3. Malignancies: Such as pheochromocytoma and respiratory diseases. 4. Infections and fever: Contribute to generalized secondary hyperhidrosis. Localized secondary hyperhidrosis can be due to: - Physiologic or pathologic gustatory sweating. - Central or peripheral neurologic dysfunctions. - Cold-induced sweating syndrome. - Paroxysmal localized hyperhidrosis. Generalized secondary hyperhidrosis results from metabolic disorders, infections, malignancies, or autonomic nervous system derangements.

Question 37

What is Frey syndrome and what are its clinical implications and treatment options?

Answer 37

Frey syndrome is characterized by: - Localized sweating on the lips, forehead, scalp, and nose when eating hot or spicy foods due to a trigeminovascular reflex. - It can occur after injury or surgery in the region of the parotid gland, often due to aberrant regeneration of autonomic fibers from the auriculotemporal nerve. ## Footnote **Clinical implications:** - Can present in infants and children after birth trauma or in cases of familial bilateral Frey syndrome without trauma. - Associated with conditions like cluster headaches and diabetes mellitus. **Treatment options include:** - Topical glycopyrrolate. - Aluminum chloride. - Botulinum toxin injections. - Rarely, intracranial section of the glossopharyngeal nerve or tympanic neurectomy may be considered.

Question 38

What is the cause of Frey syndrome?

Answer 38

Frey syndrome is caused by injury or surgery in the region of the parotid gland, often due to aberrant regeneration of autonomic fibers from the auriculotemporal nerve.

Question 39

What are the clinical implications of Frey syndrome?

Answer 39

Frey syndrome can present in infants and children after birth trauma or in cases of familial bilateral Frey syndrome without trauma. It is associated with conditions like cluster headaches and diabetes mellitus.

Question 40

What are the treatment options for Frey syndrome?

Answer 40

Treatment options include topical glycopyrrolate, aluminum chloride, botulinum toxin injections, and rarely, intracranial section of the glossopharyngeal nerve or tympanic neurectomy.

Question 41

How does paroxysmal localized hyperhidrosis manifest?

Answer 41

Paroxysmal localized hyperhidrosis is characterized by episodes of excessive sweating affecting the head, neck, and upper trunk.

Question 42

Who is more commonly affected by paroxysmal localized hyperhidrosis?

Answer 42

It is more common in older postmenopausal women, but can also occur in men.

Question 43

What are the contributing factors for paroxysmal localized hyperhidrosis?

Answer 43

Contributing factors include alterations in the hypothalamic set point temperature range for sweating.

Question 44

What are the treatment options for paroxysmal localized hyperhidrosis?

Answer 44

Treatment options include clonidine and topical or oral glycopyrrolate.

Question 45

What is eccrine nevus?

Answer 45

Eccrine nevus is a rare skin hamartoma characterized by focal hyperplasia or hypertrophy of eccrine glands.

Question 46

What are the clinical features of eccrine nevus?

Answer 46

Eccrine nevus presents as a hyperhidrotic isolated patch of skin without epidermal changes, frequently located on the forearm.

Question 47

What are the treatment options for eccrine nevus?

Answer 47

Treatment options depend on severity and may include botulinum toxin injections and topical glycopyrrolate.

Question 48

What are some metabolic disorders associated with generalized secondary hyperhidrosis?

Answer 48

Metabolic disorders include diabetes mellitus, hypoglycemia, thyrotoxicosis, carcinoid syndrome, hyperpituitarism (acromegaly), congestive heart failure, dumping syndrome, menopause, malignancy, and drug withdrawal.

Question 49

What are some infectious disorders associated with generalized secondary hyperhidrosis?

Answer 49

Infectious etiologies include tuberculosis, malaria, brucellosis, subacute bacterial endocarditis, and Hodgkin lymphoma (excessive IL-6).

Question 50

What is Riley-Day Syndrome?

Answer 50

Riley-Day Syndrome, also known as Familial dysautonomia (FD), is an autosomal recessive disorder affecting 1 in 3600 live births in the Ashkenazi Jewish population.

Question 51

What genetic mutation is associated with Riley-Day Syndrome?

Answer 51

Riley-Day Syndrome is associated with mutations in the IKAP gene on chromosome 9.

Question 52

What are the clinical features of Riley-Day Syndrome?

Answer 52

Clinical features include profuse sweating and salivation, diminished production of tears, red blotching of the skin, absence of fungiform papillae of the tongue, episodic orthostatic hypotension, arterial hypertension, reduced deep tendon reflexes, and behavioral abnormalities.

Question 53

What medications are known to cause hyperhidrosis as a side effect?

Answer 53

Medications include serotonin (5-hydroxytryptamine) reuptake inhibitors, opioids, and prostaglandin inhibitors (e.g., naproxen).

Question 54

What is the mechanism by which opioids cause hyperhidrosis?

Answer 54

Opioids can cause mast cell degranulation and histamine release, leading to hyperhidrosis.

Question 55

What are the diagnostic steps for secondary hyperhidrosis?

Answer 55

Diagnostic steps include a thorough clinical history and physical examination, obtaining baseline vital signs, and conducting laboratory studies as warranted.

Question 56

What are the causes of anhidrosis?

Answer 56

Causes include congenital absence of sweat glands (e.g., hypohidrotic ectodermal dysplasia), connective tissue diseases (e.g., Sjögren syndrome), eccrine duct obstruction, underlying neurologic disorders, peripheral neuropathies, and medications or toxins.

Question 57

What is the pathophysiological mechanism behind generalized hyperhidrosis in diabetes mellitus?

Answer 57

Generalized hyperhidrosis in diabetes mellitus may result from autonomic neuropathy, which disrupts normal sweat regulation.

Question 58

What cytokine is implicated in night sweats in Hodgkin lymphoma?

Answer 58

Interleukin-6 (IL-6) is implicated, as it induces fever and night sweats by elevating the thermal set point.

Question 59

What is the genetic mutation associated with familial dysautonomia?

Answer 59

Familial dysautonomia is associated with mutations in the IKAP gene on chromosome 9.

Question 60

What is the mechanism behind hyperhidrosis in patients taking serotonin reuptake inhibitors?

Answer 60

The likely mechanism is 5-hydroxytryptamine (2A) receptor antagonism, which can stimulate sweat production.

Question 61

What are the potential infectious etiologies that could present with generalized hyperhidrosis?

Answer 61

Potential infectious etiologies include tuberculosis, malaria, brucellosis, subacute bacterial endocarditis, and Hodgkin lymphoma.

Question 62

How does Familial Dysautonomia manifest in patients?

Answer 62

Familial Dysautonomia is characterized by profuse sweating and salivation, diminished production of tears, red blotching of the skin, absence of fungiform papillae of the tongue, episodic orthostatic hypotension, arterial hypertension, reduced deep tendon reflexes, and behavioral abnormalities.

Question 63

What role do medications play in causing hyperhidrosis?

Answer 63

Medications that can cause hyperhidrosis include serotonin reuptake inhibitors, opioids, and prostaglandin inhibitors.

Question 64

What are the clinical features of acquired idiopathic generalized anhidrosis (AIGA)?

Answer 64

AIGA is characterized by acute onset, cholinergic urticaria, elevated serum immunoglobulin E levels, absence of other autonomic dysfunction, and marked response to glucocorticoids.

Question 65

What are the types of miliaria and their distinguishing features?

Answer 65

Miliaria is classified into three types: Miliaria Crystallina (ductal obstruction at the stratum corneum), Miliaria Rubra (deeper obstruction within the epidermis), and Miliaria Profunda.

Question 66

What is the primary cause of Miliaria Profunda?

Answer 66

The primary cause of Miliaria Profunda is obstruction of eccrine sweat ducts, leading to symptoms in hot and humid conditions.

Question 67

What are the treatment options for Miliaria Profunda?

Answer 67

Treatment options include topical application of anhydrous lanolin and prevention strategies such as controlling exposure to heat and humidity.

Question 68

What is hypohidrotic ectodermal dysplasia?

Answer 68

Hypohidrotic ectodermal dysplasia is characterized by abnormal development of eccrine sweat glands, hair, and teeth, and is associated with life-threatening hyperpyrexia.

Question 69

What defines congenital insensitivity to pain with anhidrosis (CIPA)?

Answer 69

CIPA is a rare autosomal recessive disorder characterized by congenital insensitivity to noxious stimuli, anhidrosis, recurrent hyperpyrexia, and mental retardation.

Question 70

What are the early and later manifestations of Fabry disease?

Answer 70

Early manifestations include hypohidrosis, telangiectasia, angiokeratoma, acroparesthesia, and gastrointestinal symptoms. Later manifestations involve renal, cardiac, and central nervous system dysfunction.

Question 71

What are the clinical features of acquired idiopathic generalized anhidrosis (AIGA)?

Answer 71

Clinical features include acute onset, cholinergic urticaria, elevated serum immunoglobulin E levels, and absence of other autonomic dysfunction.

Question 72

What are the management strategies for Miliaria Profunda?

Answer 72

- Identify and address the primary cause of Miliaria Profunda. - Discontinue any contributing medications. - Keep the patient cool to prevent life-threatening overheating. - Advise wearing wet clothing during physical activity.

Question 73

What are the diagnostic steps for Miliaria Profunda?

Answer 73

1. Careful medical history, focusing on medications, underlying medical conditions, and family history. 2. Biopsy to identify possible sweat gland abnormalities.

Question 74

What are the treatment options for Miliaria Profunda?

Answer 74

- Topical application of anhydrous lanolin. - Prevention strategies such as controlling exposure to heat and humidity, treating any underlying febrile illnesses, and removing occlusive clothing.

Question 75

What is the likely mechanism of generalized anhidrosis in systemic sclerosis?

Answer 75

Generalized anhidrosis in systemic sclerosis may result from eccrine duct obstruction due to skin fibrosis.

Question 76

What are the primary types of focal hyperhidrosis?

Answer 76

- Palmoplantar hyperhidrosis - Axillary hyperhidrosis - Craniofacial hyperhidrosis - Generalized hyperhidrosis

Question 77

What are some secondary causes of focal hyperhidrosis associated with central nervous system disorders?

Answer 77

- Cerebral infarction - Frontal opercular infarct - Brainstem stroke - Chiari type I and II malformation - Myelopathies caused by infarction, syringomyelia, or tumor - Cold-induced sweating syndrome - Olfactory hyperhidrosis

Question 78

What are the primary autonomic disorders associated with acquired anhidrosis?

Answer 78

- Progressive isolated segmental anhidrosis - Idiopathic pure sudomotor failure - Chronic idiopathic anhidrosis - Isolated sudomotor disorders (e.g., Ross syndrome, pure autonomic failure, autoimmune autonomic neuropathy)

Question 79

What are some secondary autonomic disorders associated with anhidrosis?

Answer 79

- Central nervous system lesions (e.g., stroke, tumor, infection) - Degenerative disorders (e.g., multiple system atrophy, Parkinson disease) - Peripheral nerve lesions (e.g., hereditary sensory and autonomic neuropathy, Guillain-Barré syndrome)

Question 80

What are some conditions associated with generalized hyperhidrosis?

Answer 80

- Hyperthyroidism - Diabetes mellitus - Hypoglycemia - Hypercortisolism - Acromegaly - Malignancies (e.g., leukemia, lymphoma)

Question 81

What is the likely mechanism of miliaria in atopic dermatitis?

Answer 81

Miliaria in atopic dermatitis may result from obstruction of eccrine sweat ducts due to inflammation and skin barrier dysfunction.

Question 82

What is the underlying cause of generalized anhidrosis in Sjögren syndrome?

Answer 82

Generalized anhidrosis in Sjögren syndrome may result from autoimmune destruction of eccrine sweat glands.

Question 83

What is the pathophysiological mechanism of hypohidrosis in Fabry disease?

Answer 83

Hypohidrosis in Fabry disease results from glycosphingolipid accumulation in eccrine sweat glands and autonomic neuropathy.

Question 84

What is the pathophysiological mechanism of anhidrosis in diabetic autonomic neuropathy?

Answer 84

Anhidrosis in diabetic autonomic neuropathy results from damage to autonomic nerves that regulate sweat glands.

Question 85

What is the likely mechanism of anhidrosis in amyloidosis?

Answer 85

Anhidrosis in amyloidosis may result from deposition of amyloid in autonomic nerves, impairing sweat gland function.

Question 86

What is the underlying cause of compensatory hyperhidrosis after sympathectomy?

Answer 86

Compensatory hyperhidrosis occurs due to disruption of normal autonomic pathways, leading to excessive sweating in untreated areas.

Question 87

What is the pathophysiology of unilateral facial anhidrosis in Harlequin syndrome?

Answer 87

Harlequin syndrome is caused by disruption of sympathetic innervation to one side of the face, leading to anhidrosis and flushing.

Question 88

What is the likely cause of localized hyperhidrosis in burning feet syndrome?

Answer 88

Localized hyperhidrosis in burning feet syndrome is likely due to autonomic dysregulation affecting eccrine sweat glands.

Question 89

What is the likely mechanism of generalized anhidrosis in Parkinson disease?

Answer 89

Generalized anhidrosis in Parkinson disease may result from autonomic failure due to neurodegeneration.

Question 90

What is the underlying defect in increased chloride concentration in sweat in cystic fibrosis?

Answer 90

Increased chloride concentration in sweat in cystic fibrosis is due to defective CFTR protein, which impairs chloride reabsorption in sweat glands.

Question 91

What is the pathophysiology of segmental anhidrosis in Ross syndrome?

Answer 91

Ross syndrome is characterized by segmental anhidrosis due to autonomic dysfunction affecting sweat glands.

Question 92

What is the likely mechanism of anhidrosis in Guillain-Barré syndrome?

Answer 92

Anhidrosis in Guillain-Barré syndrome may result from autonomic nerve damage due to demyelination.

Question 93

What is the likely mechanism of generalized anhidrosis in hypothalamic lesions?

Answer 93

Generalized anhidrosis in hypothalamic lesions may result from disruption of central autonomic pathways that regulate sweating.

Question 94

What is the underlying cause of generalized anhidrosis in multiple system atrophy?

Answer 94

Generalized anhidrosis in multiple system atrophy results from widespread autonomic failure due to neurodegeneration.

Question 95

What is the likely mechanism of anhidrosis in Lambert-Eaton myasthenic syndrome?

Answer 95

Anhidrosis in Lambert-Eaton myasthenic syndrome may result from impaired autonomic nerve function due to autoantibodies against voltage-gated calcium channels.

Question 96

What is the likely cause of localized hyperhidrosis in erythromelalgia?

Answer 96

Localized hyperhidrosis in erythromelalgia may result from autonomic dysregulation affecting sweat glands.

Question 97

What is the likely mechanism of anhidrosis in systemic sclerosis?

Answer 97

Anhidrosis in systemic sclerosis may result from fibrosis and obstruction of eccrine sweat ducts.

Question 98

What are the primary causes of focal hyperhidrosis?

Answer 98

**Primary causes of focal hyperhidrosis** include: - Palmoplantar, axillary, craniofacial, and generalized hyperhidrosis.

Question 99

What are the secondary causes of focal hyperhidrosis?

Answer 99

**Secondary causes of focal hyperhidrosis** can be due to: - Cerebral infarction (e.g., frontal opercular infarct, brainstem stroke). - Spinal cord injury (e.g., autonomic dysreflexia, posttraumatic syringomyelia). - Other central nervous system disorders (e.g., Chiari malformation). - Peripheral nervous system disorders (e.g., peripheral motor neuropathy).

Question 100

How do secondary autonomic disorders associated with anhidrosis differ from primary autonomic disorders?

Answer 100

**Secondary autonomic disorders associated with anhidrosis** include: - Central nervous system lesions (e.g., hypothalamic lesions, brainstem lesions). - Degenerative disorders (e.g., multiple system atrophy, Parkinson disease). **Primary autonomic disorders with acquired anhidrosis** include: - Progressive isolated segmental anhidrosis. - Idiopathic pure sudomotor failure. - Chronic idiopathic anhidrosis.

Question 101

What are some common causes of generalized hyperhidrosis associated with central nervous system disorders?

Answer 101

Common causes of **generalized hyperhidrosis** associated with central nervous system disorders include: - Episodic hypothermia with hyperhidrosis (Hines-Bannick or Shapiro syndrome). - Posttraumatic or posthemorrhagic diencephalic epilepsy. - Fatal familial insomnia and Parkinson disease. - Infections such as tuberculosis, malaria, brucellosis, and endocarditis. - Metabolic disorders like hyperthyroidism and diabetes mellitus.

Question 102

What are the clinical implications of peripheral nerve lesions causing anhidrosis?

Answer 102

**Peripheral nerve lesions causing anhidrosis** can lead to: - Loss of sweat production in affected areas, impacting thermoregulation. - Conditions such as hereditary sensory and autonomic neuropathy, Guillain-Barré syndrome, and diabetic autonomic neuropathy. - Symptoms like heat intolerance and increased risk of heat-related illnesses.

Question 103

What are the potential effects of medications on sweating and anhidrosis?

Answer 103

Medications can cause **anhidrosis** through various mechanisms, including: - **Anticholinergics** and ganglionic blockers, which inhibit sweat gland activity. - **Opioids** and other narcotics, which can alter autonomic function. - **Heat exposure** and pharmacologic agents leading to heat-related illnesses.