This presentation was done on 2022 December 13 to the department of dermatology in National Medical College Nepal. presentation Discussed on various subtopics . Introduction Skin innervations Sensory innervation Autonomic nervous system Neurophysiological testing for skin innervation Neurological conditions Neuropathic ulcer Syringomyelia Spinal dysraphism Dermatoses associated with spinal cord injury Hereditary sensory and autonomic neuropathies Sympathetic nerve injury Complex regional pain syndrome Horner syndrome, Gustatory hyperhidrosis Restless legs syndrome/burning feet syndrome Key references

1. To
The Department of Dermatology
National medical college Birgunj
Presenter
Dr. Ramji Ram
MBBS intern at NMCTH

2.  Introduction
 Skin innervations
 Sensory innervation
 Autonomic nervous system
 Neurophysiological testing for skin innervation
Neurological conditions
 Neuropathic ulcer
 Syringomyelia
 Spinal dysraphism
 Dermatoses associated with spinal cord injury
 Hereditary sensory and autonomic neuropathies
 Sympathetic nerve injury
 Complex regional pain syndrome
 Horner syndrome,
 Gustatory hyperhidrosis
 Restless legs syndrome/burning feet syndrome
 Key references

3. Neurocutaneous disorders associated with
 Sensory abnormalities
 Autonomic abnormalities
 Overlap/mixed abnormalities
Skin manifestations may occur where the pathology is in
 Central nervous system
 Peripheral nervous system

8. Afferent sensory nerve Efferent autonomic nerve
Contains receptors for touch, temperature,
pain, itch and various other physical and
chemical stimuli
Comprises postganglionic cholinergic
parasympathetic nerves, adrenergic and
cholinergic sympathetic nerves
1 cm2 of skin innervate 1000 such
afferent neurons
Maintaining cutaneous homeostasis by
regulating vasomotor function, pilomotor
activity and eccrine gland secretion.
Sensory Neurons are unipolar, and each
branches off with a single axon travelling
towards the skin
Postganglionic fibers originate in the
sympathetic chain and are co‐distributed
with the sensory neurons until they
arborize into plexuses around sweat
glands, blood vessels and arrector pili
muscles

9.  Lewis described the capacity of the cutaneous microcirculation to vasodilate in response to direct
stimulation with a firm mechanical stroke or with a dermographometer (the axon reflex)
 The axon reflex, known as ‘antidromic vasodilation’, does not occur in chronically denervated skin, or in
skin in which neuropeptides have been depleted by capsaicin.
 The antidromic vasodilation and plasma extravasation
 Histamine via H1 and H2 receptors to produce vasodilatation and increased vascular permeability

10.  Definition : A neuropathic ulcer is a form of chronic ulceration which develops in anaesthetic skin.
Characteristically, neuropathic ulcers are painless, persistent and uninflamed, appearing on areas
subject to trauma or pressure.
 The vast majority of neuropathic ulcers occur in patients with type II diabetes
 Incidence and prevalence : people with diabetes, 25% develop foot ulcers at some point in their lives
.The annual incidence of diabetic foot ulcers is ∼3%
 Pathophysiology : Peripheral neuropathy, and ischemia secondary to peripheral vascular
disease. In diabetic patients, hyperglycemia leads to a complex of abnormal enzyme activity which
results in a decrease in normal neuron conduction as well as nerve dysfunction and ischaemia, causing
further injury to, and eventual death of, nerve cells.

11. Clinical features
Site: foot, under the metatarsal heads or on the heel.
Feature : surrounded by thick hyperkeratosis, and have a pink
punched‐out base that bleeds easily and is painless.
The changes- pes cavus and clawed toes
anaesthetic, warm with palpable pulses and dilated veins.
Neuro‐ischaemic limbs are usually cool, discoloured and prone
to ulceration on the foot margins.

12. Classification of severity:
Developed by the International Consensus of the Diabetic Foot
assesses patients for ischemia, neuropathy, linear
measurement of wound diameters, depth of wound
and infection.
Complications and comorbidities:
-Cellulitis or deep infection
-Abscess formation
- osteomyelitis.

13. Investigations:
 Reduced sensations of light touch and vibration, and
sharp–blunt discrimination.
 Palpable bone at the base of an ulcer on wound probing
is an excellent predictor of osteomyelitis.
 Plain X‐rays: may show periosteal reactions or
osteolysis, and will also identify foreign bodies, tissue
gas or bony abnormalities.
 A sinogram: sinus with a joint or a subfascial plantar
abscess.
 A radio‐isotope bone scan, or MRI scan
Management: Multidisciplinary foot care team with the
engagement of patients and carers, which can reduce
amputations by up to 70%.

15.  Definition : conditions involving abnormal fluid cavities within the spinal cord. A
‘syrinx’ is a fluid‐filled cavity within the spinal cord parenchyma.
 Synonyms and inclusions: (Hydromyelia , Spinal cord cyst, Morvan disease,
Syringohydromyelia )

16.  Syringomyelia is a rare disorder
characterized by a longitudinal cyst in the
cervical cord and/or medulla (syringobulbia)
immediately anterior to the central canal
which spreads, usually asymmetrically, to
each side.
 The CNS disturbance causes dissociated
sensory loss, with pain and temperature
sensation being lost early in the fingers and
upper limbs.

18. First clinical manifestation: painless burns and cuts on the
hands and forearms.
 Incidence and prevalence : 8.4 cases per 100 000 population.
 Age: 20-30 yrs
 Associated diseases: Chiari malformation type 1
Pathophysiology: Idiopathic, associated with Chiari
malformation type 1 , proposed that syrinx development,
particularly in CM‐1 patients,
 Follows a differential between intracranial pressure and spinal
pressure caused by a valve‐like action at the foramen magnum

19.  Clinical features:
 A short neck and a low hairline
 Pain and temperature fibers leads to a characteristic dissociated sensory loss, where pain and
temperature sensation is lost early in the upper limbs
 Sensory modalities carried in the posterior columns (e.g. touch, vibration and position sense)
remain relatively intact.
 Painless burns and cuts on the hands and forearms.
 .

20.  Investigations: MRI scanning of the hindbrain and
upper spinal cord is best for delineation of the syrinx
Management :
 A neurosurgical and orthopaedic evaluation is
warranted for all patients with a syrinx.
 Surgical indications have been stated as: progression
of motor/sensory loss, scoliosis, associated pain and
size of the syrinx

21.  Definition and nomenclature: Neurological
disorders involving the malformation of the spinal cord due to a
failure of symmetrical fusion of the embryological spinal structures
are referred to as spinal dysraphisms.
Spinal cord development occurs between 2-6th week of embryonic life.
Dysraphism is the failure of fusion between symmetrical embryological
structures (a raphe) , leading to malformations of the midline dorsal
structures

22. Spinal dysraphisms 2 subsets:
1.Open – exposed to the environment (e.g. spina bifida, myelomeningocoele
or MMC);
2. Closed – covered by intact skin.
Predisposing factors:
 Ideopathic : Genetics, folate deficiency, antiepileptic drugs (sodium valproate,
carbamazepine) and environmental conditions such as radiation
 Folate deficiency is a major cause of open dysraphism, largely preventable by
folate supplementation before conception and during early pregnancy.

24. Pathology :
 Dysraphisms occur at three stages of embryogenesis:
 Primary neurulation, secondary neurulation and gastrulation.
Investigations:
 Estimation of α‐fetoprotein in the amniotic fluid or maternal serum.
 Spinal sonography is a useful screening method in the first 4 months in
newborns.
Management:
 Initial treatment is with saline gauze at 37oC, and non‐permeable
dressings .
 Early closure of the neural tube defect and the skin without any undesirable
tension within 24–48 h.

26.  Definition :Spinal cord injury leading to a spinal cord
defect results in multiple disabilities which can be
complicated by skin problems.
 C1–C3- ventilator dependence
 The skin of patients with spinal cord injury is prone to a
number of inflammatory Dermatoses and disorders of
sweating.

27. Clinical feature :
 Seborrhoea and seborrhoeic dermatitis have been reported in quadriplegic
patients.
 Nummular eczema-occur below the level of the lesion.
 Acne on the back and buttocks- follow the onset of paralysis.
 Changes in eccrine sweating after spinal cord injuries are complex
 Profuse sweating on the face, neck and upper trunk with lesions at or above T6
may occur in exaggerated response to stimuli such as bowel or bladder distension
(autonomic dysreflexia).
 Others ptients develop sweating of the face and arms after dizziness due to
postural hypotension.
 Post‐traumatic syringomyelia can lead to hyperhidrosis
 Dryness of the skin, particularly on the soles, as an effect of anhidrosis.
 Management: -Correction of deformity if possible
- Symptomatic treatment

28.  Classification:
 HSAN type I (HSAN I): Thévenard disease
 HSAN type II (HSAN II): Riley–Day syndrome
 HSAN type III (HSAN III): familial dysautonomia
 HSAN type IV (HSAN IV)
 HSAN type V (HSAN V)
Clinical features :
 Depressed reflexes
 Altered pain and temperatures perception
 Postural hypotension
 Symptoms of GERD
 Excessive sweating

29. Differential diagnosis : LeschNyhan syndrome ,Untreated
phenylketonuria. Diabetic neuropathy .
Investigations: Genetical assessment
Management : Ambient temperature must be controlled
Protective aids, A greasy emollient applied regularly to the
skin of neuropathic limbs may moderate callus formation.

30. Image from internet

31. Definition:
 Interruption of the sympathetic innervation of the skin resulting in
loss of both vasoconstrictor impulses (causing erythema) and
sweating (causing anhidrosis)
 Loss of sympathetic supply to the skin following nerve damage will
result in vasodilation and anhidrosis
Pathophysiology :
 Sympathetic nerve injury usually occurs when sympathetic
axons are injured by trauma affecting major nerves. There
can be dissociation of sudomotor and pilomotor activity after
sympathetic ganglionectomy

32.  Clinical feature :
 Erythema with passive vasodilation.
 Anhidrotic.
 Skin becomes scaly and fissured
 Hyperasthesia , severe peripheral
neuropathy, neurotrophic ulcer.
 Hyperpigmentation of skin

33. Investigations: physically examination for
sweating, temperature, allodynia and hyperalgesia.
Pupillary examination is indicated.
 Laboratory tests include the SSR (sympathetic skin
response) , thermoregulatory sweat test (TST),
quantitative sudomotor axon reflex test (Q‐SART),
skin wrinkling on water immersion, and
microneurography.
 Management : Repair of damaged nerve(s).

35.  Complex regional pain syndrome (CRPS) is a
debilitating, painful condition in a limb, commonly
arising after physical injury, associated with
sensory, motor, autonomic nerve problems, along
with abnormalities in the bone and skin of the
affected limb.
Epidemiology:
European incidence rate of CRPS is 26/100 000
person‐years
Common in 30–50‐year age group.
Women predominate in a ratio of 4 : 1

36. Image from internet

37. Pathophysiology :
 Abnormalities in the peripheral and central nervous systems
have been described, with and without major nerve lesions.
 sympathetic dysfunction.
 CRPS is not associated with a history of preceding
psychological problems, or with somatization or malingering.
 Release of neuropeptides from peripheral unmyelinated fibres
which causes pain and vasodilation.
 Other proposed pathogenetic pathways are an enhanced
α‐adrenergic receptor activity, and up‐regulation of afferent
nocioreceptors in response to norepinephrine release from
sympathetic efferents.
 Excessive inflammation at the injury site.

38. Predisposing factors:
 Stroke, myocardial infarction, tuberculosis,
herpes zoster and certain drugs may
predispose to CRPS.
 Dermatological conditions such as vasculitis
and panniculitis may precede the condition.
Excisional skin biopsies, including nail
biopsies, have been reported as triggering

40. Clinical features: 2 Types
 Type I CRPS : (the more common) a major nerve lesion is absent
 Type II CRPS : (the less common) a major nerve lesion is present
 CRPS usually affects one limb, Onset of symptoms is usually within 1 month of the
trauma or immobilization of the limb.
 Symptoms fall into three stages

41.  Stage I : –begins after several days or weeks and lasts
about a month,
 Symptoms: spontaneous burning and stinging, or
tearing or shooting, pain, precipitated by mechanical
stimuli such as bathing, clothing on the skin or
draughts.
 Stage-II : 7 months after injury and lasts 3–6 months
 Symptoms: cool, oedematous skin, hyperhidrosis and
cyanosis, or livedo‐like change, Hair growth may
increase or decrease. Nails may show decreased or
increased growth or thickening, become brittle or
develop striations.
 Pain is variable, and neuralgia may either spread or
decrease.

42. Stage : III - starting around 8 months after injury
 progressive tissue damage, which can become permanent. The changes
may be due to vasoconstriction (resulting in skin hypoxia) or decreased
motion of the skin from inactivity of underlying joints, tendons or
ligaments. Usually, the skin becomes shiny, atrophic and dry; fingertips
may shrink. Deeper structures, including fascia, can thicken, resulting in
contractures. If the pain is worsened by physical stimuli, the patient may
protect the limb leading to trophic changes in the bone, muscle and skin
(Sudeck atrophy).
 Differential diagnosis: arthritis and arthrosis, to bone, soft‐tissue
or neural injury.
 Investigations: Needle electromyography and nerve conduction, CT or MRI
scans, Bone scintigraphy

44. Horner syndrome follows partial or complete
interruption of the sympathetic nerve
pathways of the face. It is characterized by
ptosis, miosis and anhidrosis.
Horner syndrome appears when the
three‐neuron sympathetic pathway is
interrupted anywhere from the posteriolateral
nuclei of the hypothalamus, through the
spinal cord, to the eye.

45. Clinical feature
 An irritative phase
 It can be either congenital or acquired
 Transient unilateral hyperhidrosis and vasoconstriction.
 paralytic phase:
 Involves drooping of the eyelid (ptosis) with narrowing of the palpebral fissure.
 The pupil is small, but shows normal reflex constriction to light and accommodation.
Inflamation of the conjunctiva is often present. Sweating is absent on the ipsilateral side
of the face.
 slight retraction of the eyeball into the orbit –enophthalmos
 Bilateral cases are rare. Sweat glands on the medial and lateral parts of the forehead are
innervated separately, the former by fibres from the sympathetic plexus of the internal
carotid, and the latter from the plexus surrounding the external carotid [5]. This
explains the findings in Raeder syndrome, where damage involving the perivascular
plexus of the internal carotid leads to anhidrosis only medially on the forehead .

46. Image from internet

47. Investigations:
 Physical examination and pupil dilatation test
 X‐ray, MRI, and blood or urine tests might be
needed.
Management:
Treatment should be directed towards the
underlying cause.

48.  Gustatory hyperhidrosis describes excessive
sweating occurring immediately after eating spicy
or hot food.
 Gustatory sweating is localized to certain areas,
including the scalp, upper lip, perioral region and
sternum.
Pathophysiology:
 complicate surgery involving the parotid gland or
the temporomandibular joint.
 Auriculotemporal nerve injury following closed
treatment for maxillomandibular joint trauma

49.  In the neck, for example, following damage to
the sympathetic cervical trunk and the vagus
(parasympathetic) during thyroidectomy or
after trauma, such reinnervation may result in
gustatory hyperhidrosis, even with bland
foods
Secretory sweating- frequently seen after
endoscopic transthoracic sympathectomy.

51. Clinical features
 Immediately following the ingestion of spicy or hot
food, sweating occurs which is localized to certain
areas, typically the scalp, upper lip, perioral region or
sternum.
 Frey syndrome describes gustatory sweating and
facial flushing and emerges between 3 and 24
months after surgery involving the parotid or
temporomandibular joint.
Investigations:
 Minor starch iodine test and infrared thermography

52. Management:
Topical aluminium chloride hexahydrate can
control the symptom.
 Botulinum toxin has been shown to be
effective and safe in gustatory sweating.
 0.5% aqueous solution of glycopyrronium
bromide topically in diabetes ‐associated
gustatory sweating.

54. Restless legs syndrome (RLS) is characterized by an
uncomfortable twitching sensation in the leg muscles
when sitting or lying down, which is only relieved by
moving the legs.
Burning feet syndrome (BFS) is characterized by a
burning and aching sensation of the feet
(hyperesthesia), accompanied by vasomotor changes
causing excessive sweating.
 Associated autonomic features include dry skin, eyes
and mouth, and vasomotor symptoms with peripheral
coldness, burning or flushing, hypertension and
impotence.

55.  Epidemiology:
 Incidence : One population study estimated 7.2%
to have had RLS symptoms at least weekly during
the preceding year;
 Age: 30 and 40 years
 Sex: Both conditions are more prevalent in females

56. Predisposing factors
 • Diabetes.
 • Chronic kidney disease (uraemia).
 • Vitamin deficiency (B12 and occasionally B6).
 • Alcohol abuse.
 • Hypothyroidism.
 • Lyme disease.
 • HIV/AIDS.
 • Amyloid polyneuropathy.
 • Drug side effects, including chemotherapy drugs, vitamin B6 overdose, HIV
medicines, isoniazid, amiodarone, metformin and others.
 • Heavy metal poisoning (lead, mercury, arsenic).
 • Vasculitis.
 • Sarcoidosis.
 • Guillain–Barré syndrome.
 • Arterial disease.
 • Hypertension.

57. Clinical features:
 RLS is characterized by leg paraesthesiae
associated with an irresistible urge, occurring
at rest, to move the legs provides relief.
 Symptoms are worse at night.
 chronic sleep deprivation.
 Children may- ADHD

58. The International Restless Leg Syndrome Study Group rating scale : All 4
essential criteria must be present for a positive diagnosis
 An urge to move the legs, usually with uncomfortable or unpleasant
sensations.
 Unpleasant sensations or urges to move beginning or worsening during
rest or inactivity.
 Unpleasant sensations or urges to move, partly or totally relieved by
movement such as walking, bending, stretching, etc., at least during the
activity.
 Unpleasant sensations or urges to move, worse (or exclusively) in the
evening or night‐time.
 A recent fifth criterion stipulates that the four criteria must not be solely
explained by another medical or behavioral condition

59. Differential diagnosis:
 Restless legs syndrome
• Peripheral neuropathy
• Parkinsonism
• Nocturnal leg cramps
• Peripheral vascular disease
• ADHD in children
Burning feet syndrome
• Peripheral neuropathy
Investigations: To exclude peripheral neuropathy.

61.  Rook’s textbook of dermatology 9th edition
chapter 85.
 Images from internet