Pruritus (itch)
Definition
Aetiology
Primary (skin)
Secondary
Inflammation
Eczema (atopic)
Urticaria (hives)
Insect bites
Degenerative
Senile atrophy (older dry skin)
Infection/infestation
Scabies burrows
Dermatitis herpetiformis
Viral infections
Fungal infections
Diagnosis
Examination
Investigations
History
Dermatological
Is there a lesion or not? If not, likely secondary/systemic
Colour (erythema, pallor, jaundice)
Finger webs, wrists, groin buttocks (scabies)
wheals (urticaria), excoriations, lichenification (eczema)
blisters (dermatitis herpetiformis), flat papules (lichen planus)
Nodules, ulcers scarring
Autoimmune
Lichen planus
Drugs
Statins
ACE-I
Opiates
Antidepressants
Neoplastic
Liver
Lymphoma/leukaemia
Any carcinoma
CNS/spinal tumours
Metabolic
Fe deficiency
CKD
Liver disease
General
Pallor (anaemia), clubbing (malignancy)
Enlarged LNs, hepatomegaly (lymphoma)
Signs of hypo/hyperthyroidism
Abdominal
Liver disease (jaundice, spider naevi, hepatosplenomegaly)
Renal disease (oedema, pallor)
Masses, cachexia (malignancy)
Bloods
FBC (anaemia, infection), CRP (infection, inflammation),
U+Es (CRF), LFTs (CLD), TFTs (hypo/hyperthyroidism, glucose (DM)
Fe studies (ferritin)
Imaging
CXR, CT abdomen (masses)
Bedside
Obs (sats, RR, HR, BP, temp)
SH
Occupation, living arrangements, smoking, alcohol, diet
FH
Skin conditions
Systemic disease
DH
Drugs causing itch e.g. opiates, statins
Allergies
PMH
Known skin conditions
Atopy, psychiatric disorders
Known systemic disease e.g. DM, CLD, CKD
Site (generalised, localised), character (prickling/crawling/burning), radiation (how has it spread), associated (sensation change, rashes), timing (how long for, worsened?), exacerbating/relieving factors (creams etc), severity (ADLs e.g. disturbed sleep), anyone else itchy
Red flags - fever, weight loss, night sweats
Autoimmune
MS
Management
Primary skin disease
Secondary cause
Treat cause
Conservative
Information, advice, support
Self care advice (cleaning, transmission)
Referral if diagnosis unclear (dermatology)
Medical
Emollients
E.g. diprobase
MOA: soothes dry skin, reducing itch
Antihistamines
MOA: reduce histamine release,
reducing itch at night to aid sleep
A poorly localized, usually unpleasant
sensation which elicits a desire to scratch
Special tests
Patch testing (dermatitis)
Biopsy (dermatitis herpetiformis)
Endocrine
Pregnancy
Hypo/hyperthyroidism
Hyperparathyroidism
DM
Functional
OCD, other neuroses
Psychogenic pruritus
Schizophrenia
Vascular
Strokes
Idiopathic
Xerosis (dry skin)
Haematological
Polycythaemia vera
Haemachromatosis
Complications
Dermatological
Lichen simplex chronicus (thickened skin)
Infections (impetigo)
Psychological
Insomnia
Depression
Poor concentration
Reduced libido
Swabs
Skin scrapings