‫خارش‪:‬‬
‫ شایع ترین عالمت پوستی است که به درجات مختلفی در انواع درماتوزها و نیز‬‫گاهی دربیماریهای داخلی دیده می شود‪.‬‬
‫خارش یک حس ناخوشایند در پوست (و گاهی مخاط و قرنیه)است که ‪-‬‬
‫بیمار را وادار یا متمایل به خراشیدن یا مالیدن پوست می کند‪.‬‬
‫حس خارش توسط محرکهای مختلف شامل‪ :‬شیمیایی‪،‬حرارتی‪،‬مکانیکی‪ ،‬الکتریکی‬
‫و نیز لمس سطحی‪،‬تغییرات دما و استرس ایجاد یا تشدید می شود‪.‬‬
‫حس خارش و درد توسط انتهاهای عصبی که نزدیک جانکشن درم و‬
‫اپیدرمال است‪،‬دریافت می شود‪ .‬فیبرهای سی ‪ ،‬انتقال دهنده خارش از‬
‫رسپتورهای پوستی بوده که این فیبرهای پلی مودال و غیرمیلینه وارد شاخ‬
‫خلفی نخاع شده و با نرون ثانوی سیناپس کرده و پس از تقاطع‪ ،‬از راه‬
‫اسپینوتاالمیک به تاالموس رفته و از آنجا نرون سوم ‪،‬حس خارش را به‬
‫کورتکس می برد‪.‬‬
Histamine receptors
 H1 (smooth muscle, endothelial cells ,nerve fibers
,acute allergic responses)
 H2( gastric parietal cells secretion of gastric acid , T
helpers)
 H3 (central nervous system,presynaptic neurons
modulating neurotransmission )
 H4 (mast cells, eosinophils, T cells, dentritic cells
regulating immune responses)
 Is the most common symptom of patients coming to
dermatologic clinics.
 Causes:
 1-skin disease: (Lichen planus, pediculosis, Scabies,
Atopic dermatitis,Urticaria,…)
mild to moderate :psoriasis, seborrhea,
photodermatitis
severe: lichen planus, atopic, neurodermatitis
Rubbing: urticaria, lichen planus, post menopause
 2-Systemic.D: (CRF,CBD,…(
 3-Senile & winter .P
Systemic causes of pruritus
1-Chronic renal failure
 Most of CRF patients & 80% of hemodialysis patients
have pruritus.
 The cause is unknown (uremia, dry skin ,increased
skin mast cells & histamine release, secondary hyper
parathyroidism,aluminium overload [treatable by
desferrioxamine] ,hypervitaminose A, neuropathy,
substance –P, serotonin, ….)
‫خارش کلیوی‪:‬‬
‫ ارتباطی با سن‪،‬جنس‪،‬نژاد‪،‬مدت دیالیز و علت نارسایی کلیه ندارد‪.‬‬‫ دیالیز صفاقی کمتر از همودیالیز ایجاد خارش می کند‪.‬‬‫‪ -‬اوج خارش‪ ،‬دو روز پس از همودیالیز است و شبها شدیدتر می شود‪.‬‬
Treatment:
 -Emollient
 UVB therapy (depletes the vit.A )
 -Activated charcoal (6g/d for 8wks)
 -Renal transplantation
- parathyroidectomy, Heparin, lidocain (200mg in
100cc normal saline slow iv infusion) , mexiletine,
ion-change resins, topical capsaicin 0.025% 3-5
times daily
 -Antihistamines & topical steroides not helpful
…Treatment:
 Topical gamma-linoleic acid (2.2%, 4 times daily)
 Gabapentin(200-300 mg after each hemodialysis session)
 Cholestyramine (4-16g po qd in divided doses 30 minute
before meal)
 Ondansetron (4-8mg iv, then 4mg orally every 8 hours)
 Nalfurafine (kappa-opioid receptor agonist): 5 micro g iv 3
times a wk (post hemodialysis)
 Ketotifen (1-2 mg po qd)
 Thalidomide (100 mg po qd)
 Erythropoietin (36 U/kg sc 3 times a wk)
Treatments for pruritus of chronic renal
failure.
 2-Cholestatic biliary disease
 In 20-50% of cholestasis & hepatitis C & other hepatitis ,
primary biliary cirrhosis, primary sclerosing cholangitis,
obstructive choleducholithiasis, carcinoma of the bile duct
 Generalized, migratory, not relieved with scratching
 Worse on the hands & feet and body regions constricted by
clothing, at night
 In chronic cholestasis: can be early symptom developing
years before any other manifestations.
 Cause: unknown, percipitation of specific bile salts with
specific concentration in skin.(not always)
- Increased opioidergic neurotransmisson or
neuromodulation in the CNS (opiate agonists induce
opioid receptor-mediated scratching activity of central
origin)
Treatment:
 -Cholestyramin (powder=4g) 3 times 30 minute
before mealmay be improved pruritus in PCV &
uremia
 + rifampicin (10mg/kg/d or 300mg Bid), -UVB
phototherapy
 Naloxone (1ml=0.4mg) 0.8ml ID
 Plasmapheresis
 Ribaverin : in chronic hepatitis C
 liver transplantation
 Terfenadine & cholestyramine
 Phenobarbital (2-5 mg/kg/d) & rifampicin, ondancetron
 Antihistamine? (sedation)
 Gabapentine?
Treatments for hepatobiliary pruritus.
Naltrexone
 Mu-receptor opioid
Antagonist
 chronic pruritus of different
origins(Post –burn Itch,MF
,Drugs (starch) ,prurigo
nodularis,Chronic
urticaria,Atopic derm.
Topical Doxepin:
 Doxepin is a topical tricyclic antidepressant used for the relife of
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pruritus & pain.
Antihistamine (both H1 & H2 receptors) with anticholinergic
properties.
Indicated for moderate pruritus in patients with atopic & LSC &
other forms of dermatitis & neuropathic pain (sometimes in
combination with topical capsaicin)
Cream 5% , 4 times a day for 7-8 days
Side effects: burning, irritation, allergic C.D, drowsiness (in 20%)
& sedation.
Contraindications: category B, sensitivity, narrow angel
glaucoma, urinary retention, with MAO inhibitors
Topical capsaicin:
 A natural constituent of red chili peppers.
 Antipruritic & analgesic by desensitizing nerve
endings
 Effects on the peripheral sensory nerve endings by
depletion substance-p from C fibers. (substance-p
mediates pain impulses from peripheral sensory
neurons to the CNS)
 With repeated use: prevent heat, pain & itch
sensation.
 Therapeutic effect is observed after 1 wk
…Topical capsaicin
 In intractable localized pruritus (prurigo nodularis,
brachioradial pruritus), uremic pruritus, superficial pain
due to PHN , diabetic neuropathy, notalgia paresthetica,
pruritus ani, psoriasis
 Cream,gel, lotion 0.025- 0.075%, 4 times a day.
 Side effects: category C , itching, burning, erythema
(diminish with frequent use)
…Others:
 Gel pramoxine (1%): partial anesthesia (after few minutes)
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for 2-4 h effect (combination with 0.5-2.5% hydrocortisone
as a lotion, foam, cream or ointment)
Side effect: very low sensitization potential
Camphor (0.25-0.5%): is a ketone with a local anesthetic
effect & mild degrees of pruritus or burning.
Phenol: should not be used in pregnancy & infants less
than 6 mo.
Menthol(0.025-0.5%): alcohol compound derived from
mint (cooling effect as a result of its low boiling point)
Emollients: urea (10-20%), lactic acid (5-12%)
3-Iron deficiency anemia
 Iron deficiency: generalized or localized (especially of the
perianal or vulvar region)
Treatment of choice : Iron supplement
4-Malignancy
 The rate of malignancy in patients with pruritus of unknown
origin is the same as normal population except for :
Hodgkin lymphoma & poly cythemia vera
- Obstruction of the biliiary tree, particularly in palms & soles
(carcinoma of the head of the pancreas or bile duct)
- “Central pruritus” in brain tumors or as a consequence of
treatment (surgery, radiotherapy, chemotherapy)
- Tumors of the brain: localized pruritus of the nose
Pruritus in Hodgkin lymphoma
 25% of Hodgkin's patients have pruritus.
 Pruritus is Bizarre & Migratory. Severe, persistent
generalized pruritus=recurrence of tumor or poor
prognosis (B symptom)
- Due to release of histamine (from basophils),
leukopeptidases or bradykinin, eosinophilia, occasionally
hepatic involvement with lymphoma
 Specific treatments for lymphoma.
- Topical steroids
- Oral mirtazapine (7.5-30 mg/d)
Non –Hodgkin lymphoma:
 Less prevalent( 2%), 10% of patients will suffer from
pruritus, in the course of disease.
- Treatment: INF-a systemic
Leukemia:
- Not common (usually generalized)
Most commonly with CLL (in addition can develop
exaggerated reactions to insect bites)
 Paroxetine (selective serotonin reuptake inhibitor in
treatment of intractable pruritus such as advanced cancer)
Pruritus in PCV
 30-50% of patients have pruritus.
 Pruritus begins after exiting from water & lasts 30-60
minute(aquagenic pruritus)
 The best treatments are:
1-Anti-PGs(aspirin 300mg qd TID) rapid relief it provides for
12-24 h
2- UVB or PUVA
3- IFN-a IM
4- Antihistamines H1 or H2 receptors
Antiserotonins(cyproheptadine)?
5-Aquagenic pruritus
 The clinic is the same as PCV.
 1/3 of patients have positive family history.
 The treatment is the same as PCV.
6-Endocrine disorders (1-thyroid)
Localized P:…candidiasis
 A-hypothyroidism
Generalized P:…xerosis
Localized P:….candidiasis
 B-hyperthyroidism
Generalized P:…warmness
of skin
Endocrine (2-Diabetes mellitus)
 generalized pruritus?
scalp…neuropathy
 Only localized.P
genital…candidiasis.
Endocrine(3-Postmenopausal syndrome)
local ( in genital) or generalized with hot flushing.
evokes Rubbing.
Treatment with ethinyl estradiol (with anti Candida)
7-Immundeficiency(AIDS)
 Pruritus is one of the most prevalent symptoms in
both specific & non-specific dermatitis associated
with HIV (Scabies, pediculosis, seborrhea,
candidiasis,…)
-Eosinophilic folliculitis
8-Prenancy
 About 2-20% of pregnant women have P.
 The most common cause of pruritus is
cholestasis.
 Pruritus is one of the most common symptoms in
both specific & non-specific dermatosis of
pregnancy.
9-Neurological disorders
 Brain tumors
 Spinal cord lesions
 Brain abscess
 Multiple sclerosis
 Neuropathies(Notalgia paresthetica)
 etc
10-Psychologic disorders
 Anxiety
 Depression
 Stress
 Hysterics
 Psychotic disorders parasitophobia,(treatment
with pimozide, Risperidone, Olanzapine,….)
 etc
11-Drugs
 Mostly:Opiates,Phenothiazines,Aspirin
Tolbutamide,Erythromycine esteolate, Anabolic
hormones (esterogen,Progestron, Testosteron),Vit
B-complex,…
 Note: 1-Every drug with idiosyncratic reaction can
cause pruritus.
2-Drugs can cause pruritus months after the
initiation of use.
Evaluation of patients with pruritus of unknown
origin
 1-Complete skin examination
 2-History(drugs,internal disorders , contact with
animals, chemicals,..)
 3-Systemic review
 4-Physical examination
(adenopathy,organomegally)
..Evaluation of patients with pruritus of unknown origin
 5-Screening tests (CBC, LFTs, RFTs,TFTs,
Chest-X ray, stool occult blood)
 6-Other necessary tests
 7-Repeated history & Physical exam.
 8-Psychiatric assessment
 9-Periodic fallow up
Winter pruritus:
 Only in winter,but in any age.
 Cause:xerosis due to overhydration &using
strong detergents.
 Clinic: xerosis & criss cross pattern especially on
legs & arms.
 Exacerbating of lesions after bathing.
 Treatment: glycerin soap & emollient
Senile pruritus:
 50% of elderly(>70Y) have senile .P.
 In every seasons.
 Cause & clinic is the same as winter's.
 But other precipitating factors are:
-Drugs like diuretics,..
-Hypothyroidism
-Protein & Zinc deficiency,…
Treatment of pruritus
 No specific treatment
A- General measures:
restriction of scratching, emotional stress, intake
of caffein,caffe, tea , choclate,cola drinks,alcohol.
B-Topical treatments:
-Ice compress
-starch bath
- menthol, phenol ,comphor lotions
Continue
- emollients
- Anesthetics(only promoxin)
- Doxepin cream
- Capsaicin cream
4-Physical modalities
 UVB
 PUVA
 TENS (Trans cutaneous Electric Nerve Stimulation)
 Acupuncture
 etc
UV phototherapy
 UV phototherapy is used to treat various pruritic
conditions including:
 CRF
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AD;
HIV;
Aquagenic pruritus;
Solar, chronic, and idiopathic urticaria;
Urticaria pigmentosa;
polycythemia vera;
pruritic folliculitis of pregnancy;
Breast carcinoma skin infiltration;
Hodgkin’s lymphoma;
Chronic liver disease;
Acquired perforating dermatoses,
delusions of parasitosis most common in
senile women
During the past two decades,
pimozide has been the firstline treatment
Sulpiride risperidone
and olanzapine
., which have a relatively low
incidence of extrapyramidal
and cardiac symptoms
often prescribed to the elderly.
‫با آرزوی موفقیت برای‬
‫همکاران محترم‬
‫دکتر شاهمرادی‬