When its not just an itch…. - MM3 Admin · When its not just an itch…. SARAH KARABUS ALLSA...

When its not just an

itch….SARAH KARABUS

ALLSA 2017, PORT ELIZABETH

Welcome to Port Elizabeth!

Pruritis

From Latin meaning itching

It is a symptom, not a specific disease entity

Definition

An unpleasant sensation on the skin or mucous membranes which

one instinctively tries to relieve by scratching

Pruritis

Numerous causes

Numerous treatments

Can be trivial

Can be life-threatening

Pruritis

Numerous causes

Numerous treatments

Can be trivial

Can be life-threatening

Has a huge impact on quality of life

Pathophysiology

Neurologic pathways of itch not fully understood

Signal stimulated by a variety of neuronal mediators on sensory nerve endings in epidermis and dermal-epidermal junction

Possible itch mediators: histamine, proteases, opioids, substance P,

gastrin releasing peptide, nerve growth factor, interleukins,

prostaglandins, cathepsins

Pathophysiology

• Signal transmission occurs along the unmyelinated

peripheral C-nerve fibres (both histamine and non-

histamine sensitive fibres)

• C-nerve fibres synapse with secondary neurons

that cross over to the contralateral spinothalamic

tract to thalamus.

• From thalamus to cerebral cortex where multiple

areas in the brain are activated including those

involved in emotion as well as sensory and motor

function

Pathophysiology

Scratching inhibits pruritis by stimulating inhibitory neurons and pain

receptors

Release endogenous opiates that inhibit itch

Evaluation of the itchy patient

Itch with primary skin lesions

Itch with primary systemic disease

Case 1

16yr old

Itchy skin for a few weeks

Couldn’t sleep

G.P. diagnosed eczema

But, no response to topical corticosteroids and oral antihistamines

Examination: no rash, not pale, dry skin, generalised

lymphadenopathy, no HSM

Case 1

Further history: intermittent fever and myalgia

Case 1

Further history: intermittent fever and myalgia

Biopsy: lymphoma

Referred to oncologist

Case 2

10 year old girl referred by G.P. with uncontrolled eczema

Case 2

Epileptic

Started on carbamazepine 4 weeks prior

Examination: unwell, fever 38.8, pale, facial oedema, slightly jaundiced,

lymphadenopathy, respiratory distress and poor perfusion

Skin: generalised erythema, dry, itchy and flaking – exfoliative dermatitis

Bloods: lymphocytosis, eosinophilia, ↑ LFTs, ↑ ESR

Case 2

Epileptic

Started on carbamazepine 4 weeks prior

Examination: unwell, fever 38.8, pale, facial oedema, slightly jaundiced,

lymphadenopathy, respiratory distress and poor perfusion

Skin: generalised erythema, dry, itchy and flaking – exfoliative dermatitis

Bloods: lymphocytosis, eosinophilia, ↑ LFTs, ↑ ESR

DRESS (drug reaction, eosinophilia and systemic symptoms)

Admit ICU

Systemic steroids, protracted course in ICU

Case 2

Case 3

14 year old girl referred by G.P.

Unwell for 2 weeks

Intermittent fever and myalgia

Generalised, itchy rash

Examination: generalised maculopapular rash, scratching

uncontrollably

Not pale, not jaundiced, +generalised lymphadenopathy, RUQ

tenderness

Case 3

Case 3

Bloods

CRP 30

↑ LFT

↑ INR

↑ ESR

Lymphocytosis, eosinophilia

Infectious disease/autoimmune work up negative

Biopsy

Case 3

Bloods

CRP 30

↑ LFT

↑ INR

↑ ESR

Lymphocytosis, eosinophilia

Infectious disease/autoimmune work up negative

Biopsy: DRESS

Pruritis

Don’t forget….

10 - 50% of patients with a generalised itch, with no rash, have a systemic disease

Evaluation of the itchy patient

Itch with primary skin lesions

Itch with primary systemic disease

Itch with skin lesions

Atopic dermatitis

Bullous pemphigoid

Contact dermatitis

Cutaneous T cell lymphoma

Dermatitis herpetiformis

Dermatophyte infection

Folliculitis

Lice

Lichen planus

Lichen simplex chronicus

Psoriasis

Scabies

Sunburn

Urticaria

Xerosis

Itch with skin lesions

Atopic dermatitis

Bullous pemphigoid

Contact dermatitis

Cutaneous T cell lymphoma

Dermatitis herpetiformis

Dermatophyte infection

Folliculitis

Lice

Lichen planus

Lichen simplex chronicus

Psoriasis

Scabies

Sunburn

Urticaria

Xerosis = DRY SKIN

Itch with systemic disease

Autoimmune

Haematologic

Hepatobiliary

Infectious diseases

Malignancy

Metabolic/endocrine

Neurologic/neuropathic

Other – drug ingestion, pregnancy, neuropsychiatric, anorexia

nervosa

Itch with systemic disease

Autoimmune – dermatomyositis, linear IgA disease, Sjogren’s

Haematologic – haemachromatosis, mastocytosis, PCV, plasma cell

dyscrasias, anaemia

Hepatobiliary – biliary cirrhosis, sclerosing cholangitis, chronic pancreatitis,

drug induced cholestasis, hepatitis C

Infectious diseases – HIV, prion disease, hepatitis, parasitic diseases (giardia,

ascaris, onchocerciasis)

Malignancy – leukaemia, lymphoma, multiple myeloma, solid tumours with

paraneoplastic syndr

Metabolic/endocrine – CRF, carcinoid syndrome, hyper/hypothyroidism,

hyperparathyroidism

Neurologic – stroke, tumour, MS

Other – drug ingestion, pregnancy, neuropsychiatric, anorexia nervosa

Chronic renal disease and itch

Uremic pruritis remains one of the most frustrating and debilitating

symptoms in patients with end-stage renal disease.

50% of patients with CRF itch

Up to 80% of patients on dialysis itch

Generalised itch, sometimes localised to the back

Difficult to treat

Rx: cholestyramine, activated charcoal, thalidomide, ondansetron,

UVB, erythropoietin, renal transplant

Liver disease and itch

Itch is the presenting symptom of primary biliary cirrhosis in 50% of

patients

It occurs at some point in almost 100% of patients

Begins in an acral distribution (palms and soles) which is uncommon

for other causes of itch

Becomes generalised

Rx: cholestyramine, rifampicin, naloxone, propofol, odansetron

Malignancy and itch

Most common malignancies associated with itch:

Hodgkin lymphoma – itch can precede diagnosis by 5yrs

Non-Hodgkin lymphoma

Cutaneous T-cell lymphoma (mycosis fungoides)

Polycythema vera – aquagenic pruritis in up to 70%, may precede

diagnosis by years

Leukaemias (CLL)

Plasma cell tumours

Gastric carcinoid tumours

HIV and itch

Itch may occur secondary to the skin and systemic disorders that

are frequent in HIV infected individuals

But can also be the presenting symptoms of HIV infection itself

Drugs and itch

Many different mechanisms

Drug-induced xerosis – doxycycline, retinoids, phototoxicity

Drug side-effects – opiates, anti-neoplastic agents

Neuropathic itch

Brachioradial pruritis

Notalgia paresthetica

Post herpetic neuralgia

Neuropathic itch




Itchy, burning, stinging of dorsolateral forearms

?Neuropathy of small C-fibres/nerve impingement C5-C8

Altered sensation to temperature and pinprick

Rx : cooling, antidepressants, capsaicin, topical anaesth/ketamine,

mx of C-spine disease if present

Neuropathic itch




Unilateral, infrascapular

Burning, tingling, itchy area with dysesthesia

Often associated cervico-musculoskeletal disease, neck spasm

Rx: topical steroids, capsaicin, local anaesthetic, physio, traction,

surgery if associated spinal abnormality

Other neurological causes of itch

Multiple sclerosis

Psychogenic itch – associated with anxiety, stress, mood disorders –patients pick and scratch excessively

Delusional parasitosis (Morgellan’s disease) – false belief that he/she

is suffering from a parasitic infection

Of course….

Psychological factors may affect severity of itch of any cause.

Like yawning, scratching may be “contagious” causing one to feel the urge to scratch after seeing another person scratch.

Why is itching contagious?

Patient evaluation

The majority will have a primary skin lesion that explains the

symptoms

If the cause of the skin changes is not obvious, a biopsy should be

performed

When there is no primary skin lesion….

History

Detailed history: thyroid, liver, renal, HIV disease, malignancy

Presence of constitutional symptoms: fever, weight loss, night sweats

Travel history

Psychiatric and substance abuse history

Pruritis in other family members

Localised or generalised

Any relationship with occupation?

Any exposures to chemicals, solvents , plants, cosmetics, fragrances?

Does it wake patient at night?

Investigations

If the cause of the itch remains undiagnosed and the patient has not

responded to antipruritic therapy

FBC and differential

Fe

LFTs

TSH

U&E

CXR

HIV

Appropriate malignancy screening tests

Management

Treat the cause

Treat the co-morbidities

Treat the itch

Time, sympathy and understanding…

General anti-itch measures

Skin moisturisation - emollients

Cool the skin – cool environment, light-weight clothes, cooling lotions

Avoid skin irritants – wool, harsh cleansing products

Stress reduction

Physical interventions – occlusion, wraps, cut nails

Specific treatments for itch

Topical

Systemic

Topical therapy for itch

Topical corticosteroids

Topical calcineuron inhibitors

Doxepin (tricyclic/antihistamine)

Menthol, calamine - cooling

Capsaicin cream – neuropathic itch

Salicylic acid – lichen simplex chronicus

Local anaesthetic – neuropathic itch

Don’t use topical antihistamines or anaesthetics long term – sensitiseand cause contact dermatitis

Systemic therapy for itch

Antihistamines – urticaria and mastocytosis (but not much else)

Antidepressants – cholestatic itch, psychiatric, paraneoplastic

Doxepin

Opioid receptor antagonists – cholestatic, CRF

Anticonvulsants – gabapentin – neuropathic itch and renal failure

Thalidomide – prurigo nodularis

Phototherapy – renal, atopic eczema, psoriasis, cutaneous T-cell

lymphoma

Cognitive behavioural therapy

Hot off the press….

Xeljanz (Tofacitinib)

JAK 1 inhibitor for rheumatoid arthritis

80% improvement in itch (Cell, Sept 8. in press)

When its not just an itch…. - MM3 Admin · When its not just an itch…. SARAH KARABUS ALLSA...

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Transcript of When its not just an itch…. - MM3 Admin · When its not just an itch…. SARAH KARABUS ALLSA...