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:خارشعالمت پوستي است كه به درجات مختلفي در انواع درماتوزها و نيز گاهي شايع ترين-
.دربيماريهاي داخلي ديده مي شودش تخا د ند شا ناخ ح ه(ك ن ق خاط كه)گاه ت ‐ا است كه )و گاهي مخاط و قرنيه(يك حس ناخوشايند در پوستخارش
.بيمار را وادار يا متمايل به خراشيدن يا ماليدن پوست مي كندشيميايي،حرارتي،مكانيكي، الكتريكي و نيز :شاملمحركهاي مختلفحس خارش توسط و رش يس ه يزلر و ي ري ي ي ي ر ر يي ي ي
. لمس سطحي،تغييرات دما و استرس ايجاد يا تشديد مي شود
كه نزديك جانكشن درم و اپيدرمال انتهاهاي عصبيحس خارش و درد توسط ، انتقال دهنده خارش از رسپتورهاي فيبرهاي سي . است،دريافت مي شود
وپوستي بوده كه اين فيبرهاي پلي مودال و غيرميلينه وارد شاخ خلفي نخاع شده و ع ي خ ر و ي ي ير و ل و ي پ ي يبر ين بو ي پوسيناپس كرده و پس از تقاطع، از راه اسپينوتاالميك به تاالموس نرون ثانوي با
.،حس خارش را به كورتكس مي بردنرون سوم رفته و از آنجا
Is the most common symptom of patients coming to y p p gdermatologic clinics.
C Causes: 1‐skin disease: (Lichen planus, pediculosis, Scabies, Atopic dermatitis Urticaria )Atopic dermatitis,Urticaria,…)mild to moderate :psoriasis, seborrhea,
photodermatitissevere: lichen planus, atopic, neurodermatitis
Rubbing: urticaria, lichen planus, post menopause 2 Systemic D: (CRF CBD ) 2‐Systemic.D: (CRF,CBD,…) 3‐Senile & winter .P
Systemic causes of pruritus
1‐Chronic renal failure1‐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 parath roidism aluminium o erload [treatable b parathyroidism,aluminium overload [treatable by desferrioxamine] ,hypervitaminose A, neuropathy, substance –P, serotonin, ….)
:خارش كليوي.نداردارتباطي با سن،جنس،نژاد،مدت دياليز و علت نارسايي كليه-.از همودياليز ايجاد خارش مي كند كمتردياليز صفاقي -. پس از همودياليز است و شبها شديدتر مي شوددو روزاوج خارش،-
TTreatment:
‐EmollientEmollient UVB therapy (depletes the vit.A ) ‐Activated charcoal (6g/d for 8wks) Activated charcoal (6g/d for 8wks)
‐Renal transplantation‐ parathyroidectomy, Heparin, lidocain (200mg in parathyroidectomy, Heparin, lidocain (200mg in 100 cc normal saline slow iv infusion) , mexiletine, ion‐change resins, topical capsaicin 0.025% 3‐5 times daily
‐Antihistamines & topical steroids not helpful
Treatment:…Treatment: Topical gamma‐linoleic acid (2.2%, 4 times daily)Topical gamma linoleic acid (2.2%, 4 times daily) Gabapentin(200‐300 mg after each hemodialysis session) Cholestyramine (4‐16 g po qd in divided doses 30 minute
b f l)before meal)
Ondansetron (4‐8 mg iv, then 4mg orally every 8 hours) Nalfurafine (kappa opioid receptor agonist): 5 micro g iv 3 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 renalTreatments for pruritus of chronic renal failure.
2 Cholestatic biliary disease 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 ductobstructive choleducholithiasis, carcinoma of the bile duct
Generalized, migratory, not relieved with scratching Worse on the hands & feet and body regions constricted by y g yclothing, at night
In chronic cholestasis: can be early symptom developing b f th if t ti years before any other manifestations.
Cause: unknown, percipitation of specific bile salts with specific concentration in skin.(not always)Increased opioidergic neurotransmisson or ‐ 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 meal may be improved pruritus in PCV &
iuremia + rifampicin (10mg/kg/d or 300mg Bid), ‐UVB
h t thphototherapy Naloxone (1ml=0.4mg) 0.8ml IDPl h i 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.
3‐Iron deficiency anemiaI d fi i li d l li d ( i ll f h Iron deficiency: generalized or localized (especially of the perianal or vulvar region)
Treatment of choice : Iron supplementTreatment of choice : Iron supplement
4‐Malignancy
The rate of malignancy in patients with pruritus of unknown 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 biliiar tree particularly in palms & soles‐ 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) 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 generalized pruritus=recurrence of tumor or poor prognosis (B symptom)‐ Due to release of histamine (from basophils), ( p ),leukopeptidases or bradykinin, eosinophilia, occasionally hepatic involvement with lymphoma
S ifi t t t f l h Specific treatments for lymphoma. ‐ Topical steroids‐ Oral mirtazapine (7 5‐30 mg/d)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‐ Treatment: INF‐a systemic
Leukemia:N ( ll li d)‐ Not common (usually generalized)Most commonly with CLL (in addition can develop exaggerated reactions to insect bites)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 30‐60minute(aquagenic pruritus)minute(aquagenic pruritus)
The best treatments are:1‐Anti‐PGs(aspirin 300mg qd TID) rapid relief it provides for 1 Anti PGs(aspirin 300mg qd TID) rapid relief it provides for 12‐24 h
2‐ UVB or PUVA3‐ IFN‐a IM4‐ Antihistamines H1 or H2 receptors Antiserotonins(cyproheptadine)?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:…xerosisLocalized P:….candidiasis
B‐hyperthyroidismGeneralized P:…warmness of skin
Endocrine (2‐Diabetes mellitus) generalized pruritus? generalized pruritus?
scalp…neuropathyOnly localized POnly 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)Treatment with ethinyl estradiol (with anti Candida)
7‐Immundeficiency(AIDS)
Pruritus is one of the most prevalent symptoms in p y pboth specific & non‐specific dermatitis associated with HIV (Scabies, pediculosis, seborrhea,
d d )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 abscessMultiple sclerosisp Neuropathies(Notalgia paresthetica) etc
10‐Psychologic disorders Anxiety Depression Stress Hystericsy Psychotic disorders parasitophobia,(treatment with pimozide, Risperidone, Olanzapine,….)
etc
11‐Drugs
Mostly:Opiates,Phenothiazines,Aspirin Tolbutamide,Erythromycine esteolate, Anabolic hormones (esterogen Progestron Testosteron) Vit hormones (esterogen,Progestron, Testosteron),Vit B‐complex,…
Note: 1‐Every drug with idiosyncratic reaction can y g ycause pruritus.
2‐Drugs can cause pruritus months after the i i i i f initiation of use.
l f h f kEvaluation 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
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:p p g‐Drugs like diuretics,..‐Hypothyroidismyp y‐Protein & Zinc deficiency,…
Winter pruritus:
Only in winter,but in any age. Cause:xerosis due to overhydration & using strong detergents.
Clinic: xerosis & criss cross pattern especially on l legs & arms.
Exacerbating of lesions after bathing. Treatment: glycerin soap & emollient
Treatment of pruritus No specific treatmentA‐ General measures:restriction of scratching emotional stress intake restriction of scratching, emotional stress, intake of caffein,caffe, tea , choclate,cola drinks,alcohol.
B‐Topical treatments:p‐Ice compress‐starch bath
h l h l h l i‐menthol, phenol ,comphor lotions
Continue‐ emollients‐ Anesthetics(only promoxin)‐ Doxepin cream‐ Capsaicin creamp
Naltrexone Mu‐receptor opioid u ecepto op o dAntagonist
chronic pruritus of different origins(Post –burn Itch,MF D ( t h) i ,Drugs (starch) ,prurigo nodularis,Chronic urticaria,Atopic derm., p
Topical Doxepin:
Doxepin is a topical tricyclic antidepressant used for the relife of Doxepin is a topical tricyclic antidepressant used for the relife of pruritus & pain.
Antihistamine (both H1 & H2 receptors) with anticholinergic properties.p ope t es.
Indicated for moderate pruritus in patients with atopic & LSC & other forms of dermatitis & neuropathic pain (sometimes in combination with topical capsaicin)p p )
Cream 5% , 4 times a day for 7‐8 days Side effects: burning, irritation, allergic C.D, drowsiness (in 20%)
& sedation& sedation. Contraindications: category B, sensitivity, narrow angel
glaucoma, urinary retention, with MAO inhibitors
Topical capsaicin:Topical capsaicin:
A natural constituent of red chili peppers.A i i i & l i b d i i i Antipruritic & analgesic by desensitizing nerve endings
Effects on the peripheral sensory nerve endings by 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)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 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)
O h…Others: Gel pramoxine (1%): partial anesthesia (after few minutes) 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 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.M h l( %) l h l d d i d f 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%)Emollients: urea (10 20%), lactic acid (5 12%)
Physical modalities UVB PUVA TENS (Trans cutaneous Electric Nerve Stimulation) Acupuncturep etc
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