Ch. 6- Pruritus and Dysesthesia Flashcards
Name 8 non dermatologic causes of itch
Systemic: Renal disease, Liver/biliary disease
Infections: HIV, Hep C (liver)
Metabolic: Thyroid disease, diabetes, iron deficiency, hemochromastosis, hyperPTH
Malignancy: Lymphoma and myeloproliferative neoplasms (e.g. PCV, essential throbocytosis, HES), paraneoplastic itch
Invisible derm: Celiac, BP, Dermatographism
Neurologic: peripheral or central causes
Psychocutaneous disorders
What are the 3 major groups of pruritis
(1) affecting diseased (inflamed) skin
(2) affecting non-diseased (non-inflamed) skin;
(3) presenting with chronic secondary scratch-induced lesions
What are the 6 major causes/categories of pruritus
dermatologic
systemic
neurologic
psychogenic
mixed
other/unknown
List the workup for someone with generalized pruritus NYD
H+P: Full skin exam, LAD, look at mid back for butterfly sign
Biopsy of any lesions + peri-lesional for DIF (celiac, BP)
Bloodwork:
CBC, lytes
Renal and liver, LDH
A1C, TSH
ESR/ CRP
Consider:
Infection: HIV, Hep B/C
Stool for O+P
Iron studies, PTH/Ca/Phos
Total IgE
Celiac testing, BP ab’s
Anti-mitochondrial/smooth muscle ab’s (PBC, PSC)
SPEP/UPEP
CXR or CT chest
Abdo/pelvis US
Spinal xray or Sri for localized itch
Age appropriate cancer screening
PAtch testing or SPT
IMO lower yield:
UA
5-HIAA urine
Serum tryptase/chromogranin A
What 2 types of CTCL are most likely to cause pruritus
Sezary
Folliculotropic
Name 4 treatments for pruritus in CTCL
Gabapentinoids
Opioids-naltrexone 50-150 mg
Aprepitant
Mirtazapine
Name 5 possible underlying causes for prurigo nodularis
Derm conditions:
-AD, xerosis
Systemic condition:
-Hepatic/renal disease, hyperthyroid, lymphoma
Psych:
-OCD, anxiety, stress
NAme 10 things on the ddx for PN
Perforating dermatoses
Hypertrophic LP
Scabies nodules
Pemphigoid nodularis
Hypertrophic DLE
Persistent insect bites
Pruriginous type of dominant dystrophic epidermolysis bullosa
KA’s and granular cell tumors
Name two changes in the nerves of PN
Hypertrophy and increased density dermal nerve fibres with concomitant reduction in epidermal nerve fibres/ epidermal small fibre neuropathy”
What is the difference between primary and secondary pruritus ani?
Primary - no clear underlying cause
Secondary - underlying cause
NAme 6 causes for secondary pruritus ani
chronic diarrhea
fecal incontinence/anal seepage
hemorrhoids
anal fissures or fistulas
rectal prolapse
primary cutaneous disorders (e.g. psoriasis, lichen sclerosus, seborrheic dermatitis, allergic contact dermatitis)
sexually transmitted diseases
infestations (e.g. pinworms)
previous radiation therapy
neoplasms (e.g. anal cancer)
What is the workup for pruritus ani
Evalute psychiatric causes
Consider testing for pinworm or O+P
Lactobacillus replacement if chronic diarrhea from abx
Patch testing
Rectosigmoidoscopy
What is the workup for pruritus ani
Evalute psychiatric causes
Consider testing for pinworm or O+P
Lactobacillus replacement if chronic diarrhea from abx
Patch testing
Rectosigmoidoscopy
+- Lumbosacral MRI–> nerve compression
Name 5 treatments for primary pruritus ani
Sitz baths
Perianal hygiene- water-moistened, fragrance-free toilet paper or a bidet
Barrier creams
TCS or TCIs
Name 2 causes of aquagenic pruritus
- Most often a cause, primary is uncommon
PCV
Aquagenic urticaria
How does aquagenic pruritus present?
Aquagenic pruritus presents with prickling, tingling, burning, or stinging sensations within 30 minutes of water contact, irrespective of its temperature or salinity, and lasts for up to 2 hours
Typically, symptoms begin on the lower extremities and then generalize, with sparing of the head, palms, soles, and mucosae
on examination, specific skin lesions are not seen.
The pathologic mechanism is unknown, although elevated dermal and epidermal levels of acetylcholine, histamine, serotonin, and prostaglandin E 2 have been described 1 .
Name 10 conditions that may result in sensation of pruritus with water
(excluding primary aquagenic pruritus)
Urticaria–> dermatographic, cholinergic, aquagenic, cold-induced
Mastocytosis
Hemochromatosis
Blood causes:
Hypereosinophilic syndromes
PCV
Hodgkin disease
Myelodysplastic syndromes
Essential thrombocythemia
Testosterone-induced erythrocytosis
Drug-related (e.g. antimalarials, bupropion, clomipramine)
Aquagenic pruritus of the elderly (xerosis may be subtle)
Name 4 treatments for scar associated pruritus
Topical steroids
ILK
Silicone gel sheets
Pentoxyfiline 400 2-3 times daily
What is one systemic treatment for post burn pruritus
Gabapentin
*others include topical anesthetics, colloidal oatmeal, bathing in oil, emollients
What is the pattern of pruritus in uremic pruritus for patients on HD
usually peaks in the evening after 2 days without dialysis, is relatively high during dialysis, and is lowest the following day
What is the cause of uremic pruritus
NOT elevated levels of urea. Poorly understood.
Dramatic improvement in some patients after parathyroidectomy but not no correlations with serum PTH, Ca or Phos.
No clear correlation with xerosis.
Possibly neuropathy, as 65% of patients on dialysis have neuropathy.
Increased levels IL-31
Therapeutic ladder for uremic pruritus (Bolognia)
Y-linolenic acid 2.2% QID
0.025% three to five times daily
Pramoxine
Cromolyn sodium
Gabapentin
What are the most common hepatic causes of cholestatic pruritus
PBC
PSC
Choledocolithiasis
Cholestasis-including drug induced
Carcinoma bile duct
Chronic hep C infection (or other virus)
What are the clinical features of cholestatic pruritus
Worse at night
Hands/feet/constricted areas
Generalized, migratory and not relieved by scratching
Name 3 theories for the MOA of cholestatic pruritus
- Bile acid build up (but hepatocellular failure results in the cessation)
- Increased opioidergic neurotransmission or neuromodulation in the CNS
3.Increased LPA/Lyphophosphatidic acid (neuronal activator) and ataxin (enzyme that converts precompound to LPA)
Treatment cholestatic pruritus
*Treat underlying condition-e.g. hep C, removal gallstone, treat cancer.
- Cholestyramine
- Rifampin
- Opioid modulators-naloxone IV, naltrexone, Nalfurafine (K agonist-japan only)
- Sertraline
*some others, ultimate is liver transplant
Treatment cholestasis pregnancy
Ursodeoxycholic acid
How does iron deficiency associated anemia present
Generalized or localized, specifically perianal or vulvar
*In patients with IDA and itch, iron supplementation can help
What % patients with PCV develop aquagenic pruritus? When does it occur?
30-50%
Can occur several years before PCV develops
Treatment for PCV-aquagenic pruritus
Aspirin 81 mg po daily
What is paraneoplastic itch? What are the 3 most common causes?
A systemic reaction to the presence of a tumor or a hematological malignancy, neither induced by the local presence of cancer cells nor by tumor therapy, disappears with treatment, recurs with cancer recurrence
MC causes:
-Hematological malignancies: PCV > ET
-Hodgkins lymphoma
-non Hodgkin lymphoma
How does Hodgkins lymphoma-associated pruritus present?
Nocturnal generalized pruritus along with the other B-symptoms like fevers, chills, night sweats, weight loss
NAme 3 treatments for hodgkins associated itch other than chemo
Mirtazapine- 30 mg/day
Aprepitant
TCS
What are the 2 most common leukaemia to cause generalized pruritus
CLL
Hypereosinophilic syndromes
Name 5 endocrinopathies that can present with itch
- Hyperthyroid!
- Hypothyroid–> more related to xerosis
- Diabetes mellitus-esp perianal/vulvar area
*These are the main ones, ones below sort of extra, not as clear
4. HyperPTH
5. Hemochromatosis
What % of patients with HIV-associated itch have an underlying cause for the itch? Give 5 examples of diagnoses that could cause itch.
50%
Psoriasis
Pruritus papular eruption
Eosinophilic folliculitis
Severe seb derm
Scabies
Renal failure, liver failure
Lymhpoma
Kaposis sarcoma
Xerosis
Drug eruptions
name 4 treatments for HIV associated pruritus
Anti-histamines (High IgE, Eos and th2 inflammation in HIV pruritus)
TCS
Phototherapy
Thalidomide
Name 8 drug induced causes of itch, their category/MOA and an example
NSAIDS–> increased leukotrienes
SSRIs–> increased serotonin
ACEi–> increased bradykinin
Beta blockers–> xerosis/seebostasis
Opioids–> tramadol, codeine, morphine, fentanyl (also cocaine, meth)
*Also, immunotherapy, EGFR, MEK/BRAF inhibitors, anything causing cholestasis or hepatotoxicity
What is Dysesthesia
A dysesthesia is defined as an unpleasant abnormal sensation, such as tingling, burning, numbness, or pruritus;
What is Dysesthesia
A dysesthesia is defined as an unpleasant abnormal sensation, such as tingling, burning, numbness, or pruritus;
What is the most common cause of neurologic pruritus?
Neurologic pruritus most often results from damage, compression, or irritation affecting a nerve or group of nerves e.g. Cervical OA, radiculopathy, MS, stroke, masses, etc.
Name the 6 most common dysethesias from sensory neuropathies and their locations
Notalgia paresthetica-upper back
Meralgia paresthetica-anterolateral thigh
Brachioradial pruritus - neck/trap/dorsalateral arm and elbow
Trigeminal trophic syndrome-lateral face
Cheiralgia paresthetica-thumb/dorsal hand
Digitalgia paresthetica-dorsal D2/D3
What nerves does notalgia paresthetica come from
T2-T6
What syndrome is associated with early onset nostalgia paresthestica in childhood/teens
SIPPLE syndrome (MEN2A)
Name 2 contributing factors to brachioradial pruritus
Cervical nerve impingment
Cumulative solar damage represents another predisposing factor + acute UV light exposure exacerbates the condition and patients living in temperate climates often experience remissions during the fall and winter. Patients may relate that application of ice provides some relief, and sunscreen may help.
What nerve is impinged in meralgia paresthetica ? What are 4 contributing factors
Lateral femoral cutaneous nerves
Obesity, pregnancy, prolonged sitting, tight clothing, and carrying heavy wallets in trouser pockets. Much less often, it results from a lumbar radiculopathy.
What is Cheiralgia paresthetic
a sensory mononeuropathy of the superficial branch of the radial nerve . Patients report numbness, tingling, or burning involving the dorsoradial aspect of the hand and proximal thumb
The cause is usually trauma or pressure, e.g. from a tight wristwatch or handcuffs.
What is Digitalgia paraesthetica
sensory neuropathy affecting digital nerves of the fingers and less often the toes 87 . It results from trauma or pressure, e.g. on the fingers from carrying heavy plastic grocery bags or on the toes from long marches or hikes.
What is burning mouth syndrome
(orodynia)–> burning mucosal pain without clinically detectable oral lesions. The pain is typically bilateral, often involving the anterior two-thirds of the tongue, palate, and lower lip. The buccal mucosa and floor of the mouth are rarely involved. The histology of the affected areas in primary burning mouth syndrome is unremarkable; however, secondary causes may be identified.
Female: male 7:1
What are the 3 types of burning mouth syndrome
type 1 (35%) – absence of symptoms upon awakening, with a gradual increase in severity over the course of the day
type 2 (55%) – constant burning, both day and night; and type 3
(10%) – days of remission that follow no identifiable pattern
Name 6 conditions to check for that may be precipitating burning mouth syndrome
Deficiency in:
- iron
-zinc
-folate
- vitamin B 12 deficiencies
type 2 diabetes mellitus
hypothyroidism
menopause
Name 3 treatments for scalp dysethsaia or burning mouth syndrome
- TCA
- SSRI
- Gabapentin
- Capsaicin for scalp
What is trigeminal trophic syndrome
a self-induced ulcerative condition of the central face that classically involves the nasal Ala, sparing nasal tip
The self-mutilation is triggered by dysesthesia together with hypesthesia (diminished sensation), both resulting from damage to the sensory portion of the trigeminal nerve.
What is the cause for trigeminal trophic syndrome
Damage to trigeminal neve, often from either ablation for trigeminal neuralgia, or stroke, HSV, trauma.
What is the cause for trigeminal trophic syndrome
Damage to trigeminal neve, often from either ablation for trigeminal neuralgia, or stroke, HSV, trauma.
Name 6 cutaneous findings in complex regional pain syndrome
Edema, erythema, livedo reticularis, cyanosis, hypertrichosis, hyperhidrosis, nail dystrophy, motor dysfunction, and eventually atrophy.
