Pruritis arising secondary to underlying disease

Question 1

Generalised itch differentials without rash

Answer 1

renal pruritis
cholestatic pruritis
endocrine (thyroid disease, DM)
paraneoplastic
haematological (Fe deficiency, polycythaemia vera, Hodgkin disease, Non-Hodgkin lymphoma, leukaemia)
HIV
pregnancy-related
drug related (eg. opioids)

Question 2

Generalised itch differentials with rash

Answer 2

scabies
eczema/dermatitis
urticaria/dermographism
paraneoplastic (eg. cutaneous T/B cell lymphoma, solid tumour)
pityriasis rubra pilaris
bullous disease
psoriasis
pregnancy-related
drug eruptions

Question 3

What can cause renal pruritis and how is it managed?

Answer 3

chronic renal failure (not acute)
improves after dialysis
phototherapy, medications

Question 4

What can cause cholestatic pruritis and how is it managed?

Answer 4

any liver disease
can have normal bilirubin
typically worse on hands, feet and body regions constricted by clothing
worse at night

treat underlying cause
cholestyramine (binds to bile acids preventing re-absorption)
ursodeoxycholic acid (regulates cholesterol via absorption rated)

Question 5

What disease is koilonychia seen in?

Answer 5

iron deficiency anaemia

Question 6

Which leukaemia most commonly causes generalised itch?

Answer 6

chronic lymphocytic anaemia (CLL)