Purpuric rashes + vasculitis

Question 1

What is purpura?

Answer 1

non-blanching purple-ish rash
due to leakage of blood (haemorrhage) from skin blood vessels

Question 2

What does macular purpura normally indicate?

Answer 2

usually non-inflammatory cause

Question 3

What does palpable purpura normally indicate?

Answer 3

usually inflammatory cause (eg. vasculitis)

Question 4

4 general causes of purpura

Answer 4

trauma

platelet disorder

vascular disorder (leaky vessels)

coagulation disorder/embolic (usually ecchymoses and external bleeding)

Question 5

Which coagulation disorders/embolic can cause purpura?

Answer 5

DIC
Heparin-induced thrombocytopenia
Warfarin-induced necrosis
Septic emboli/cholesterol emboli

Question 6

2 types of non-palpable purpura

Answer 6

petechiae
ecchymoses

Question 7

Which diseases can cause petechiae?

Answer 7

thrombocytopenia (idiopathic, drug-induced, thrombotic, DIC, infection)

abnormal platelet function

increased intravascular venous pressures

some inflammatory skin diseases

Question 8

Which diseases can cause ecchymoses?

Answer 8

external trauma

DIC and infection

coagulation defects

skin weakness/fragility

Question 9

Define vasculitis

Answer 9

inflammation of blood vessel wall
can happen in small, medium and large vessels
causes leakage of blood –> purpura

Question 10

Vasculitis causes

Answer 10

idiopathic
infection
inflammatory + autoimmune disease
drugs
neoplastic

Question 11

How is vasculitis classified?

Answer 11

by size of vessel

Question 12

Which infections cause vasculitis?

Answer 12

can be any –> often after URTI

bacterial –> meningococcus

viral –> Hep B/C

Question 13

Name 2 large vessel vasculitides

Answer 13

Giant cell (temporal) arteritis
Takayasu’s arteritis

Question 14

What is GCA associated with?

Answer 14

polymyalgia rheumatica

Question 15

GCA cutaneous involvement

Answer 15

rare
usually tender nodules over superficial arteries

Question 16

GCA systemic manifestations

Answer 16

headache
jaw claudication
blindness

Question 17

Who does Takayasu’s arteritis normally affect?

Answer 17

young women

Question 18

Where does Takayasu’s arteritis affect?

Answer 18

vasculitis of aorta and aortic branches

Question 19

Describe the early phase of Takayasu’s arteritis

Answer 19

pre-pulseless systemic disease
subclavian steal syndrome
anaemia
fatigue

erythema nodosum-like nodules

Question 20

Describe the late phase of Takayasu’s arteritis

Answer 20

pulselessness with or without signs of ischaemia
hypertension
renal artery stenosis

pyoderma gangrenosum-like lesions

Question 21

Name 2 medium vessel vasculitides

Answer 21

polyarteritis nodosa
kawasaki disease

Question 22

Symptoms of polyarteritis nodosa

Answer 22

segmental arteritis
livedo reticularis + ulceration possible
generally affects lower extremities
arthralgias + myalgias (polymyositis)
polyneuritis
renal disease
hypertension
microaneurysms
5-10mm subcutaneous nodules distributed segmentally
normal/erythematous overlying skin
may be painful, pulsatile or secondarily ulcerated

Question 23

Kawasaki disease symptoms

Answer 23

prolonged fever (at least 5 days)
polymorphous cutaneous eruption (mostly trunk + extremities)
mucous membrane involvement (conjunctival, oropharyngeal)
sometimes can result in coronary artery aneurysms
macular, maculopapular, urticarial, targetoid, scarlatiniform, vesiculopapular, pustular
desquamation at week 2

Question 24

Name 3 small vessel vasculitides

Answer 24

Henoch-schonlein purpura (IgA vasculitis)
Wegener’s granulomatosis (granulomatosis with polyangiitis)
Churg-strauss syndrome (eosinophilic granulomatosis with polyangiitis)

Question 25

Who is IgA vasculitis most common in?

Answer 25

children <10

Question 26

IgA vasculitis symptoms

Answer 26

can precede URTI
symmetrical intermittent palpable purpura on extensor extremities and buttocks
arthralgias and arthritis
haematuria
abdominal pain
melaena
renal involvement
IgA immune deposition in vessel walls
usually mild + self-limiting
erythematous, urticarial papules
rapidly evolves into palpable purpura with haemorrhage in 24 hours

Question 27

Describe granulomatosis with polyangiitis symptoms and skin involvement

Answer 27

necrotising granulomatous inflammation of upper and lower respiratory tracts (otitis, epistaxis, sinusitis)

glomerulonephritis (C-ANCA +ve)

systemic vasculitis (skin + oral mucosa, pulmonary infiltrates)

painful subcutaneous nodules, papules, vesicles, petechiae, palpable purpura, pyoderma-gangrenosum-like lesions

Question 28

Describe eosinophilic granulomatosis with polyangiitis symptoms and skin involvement

Answer 28

multisystem vasculitis (asthma, eosinophilia, necrotising vasculitis with extravascular granulomas)

asthma + allergic rhinitis

vasculitis involving 2 or more extrapulmonary organs (eg. GI, heart)

palpable purpura and infiltrated nodules

can be P-ANCA +ve

Question 29

What is the most common type of vasculitis?

Answer 29

cutaneous leukocytoclastic vasculitis/cutaneous small vessel vasculitis/hypersensitivity vasculitis

(same things, different names)

Question 30

Describe cutaneous small vessel vasculitis

Answer 30

affects small vessels/post-capillary venules
women>men (children + adults)
circulating immune complexes deposited in walls of affected blood vessels
lesions on ankles/lower legs/pressure points

palpable purpura, lesions ranging 1mm-several cms
urticaria or ulcers possible

Question 31

Vasculitis investigations (history)

Answer 31

History:
- associated symptoms = haematuria, haemoptysis, sinusitis, SOB/cough

• triggers = drug/infection, constitutional symptoms

Question 32

Vasculitis examination findings

Answer 32

vital signs = pyrexial, hypertensive

distribution + description of rash - palpable?

head + neck = sinusitis, chondritis, otitis, iritis

renal = tenderness to palpation

liver = hepatosplenomegaly

pulmonary = crackles

Question 33

Vasculitis investigations

Answer 33

Basic bloods:
- FBC
- U&Es
- LFTs

Immunology:
- rheumatoid factor
- ANA
- ANCA
- Complement
- protein + Ig electrophoresis
- cryoglobulins

Infection:
- anti-hep B/C antibodies/HIV
- anti-streptococcal antibodies
- blood cultures

non-blood tests:
- urinalysis
- BP
- skin biopsy with immunofluorescence <48 hours

Imaging:
- sinus radiographs+ CT
- CXR/CT
- ECG
- ECHO

Question 34

Vasculitis treatment

Answer 34

rash can resolve spontaneously in most cases

observation

treat underlying cause (treat infection, stop medication, treat neoplasm)

rest + elevation (reduce oedema + stasis)

analgesia

protect fragile skin from injury

severe or persistent cases = corticosteroids, colchicine, NSAIDs (indomethacin), dapsone, hydroxychloroquine