Purpuric rashes + vasculitis Flashcards
What is purpura?
non-blanching purple-ish rash
due to leakage of blood (haemorrhage) from skin blood vessels
What does macular purpura normally indicate?
usually non-inflammatory cause
What does palpable purpura normally indicate?
usually inflammatory cause (eg. vasculitis)
4 general causes of purpura
trauma
platelet disorder
vascular disorder (leaky vessels)
coagulation disorder/embolic (usually ecchymoses and external bleeding)
Which coagulation disorders/embolic can cause purpura?
DIC
Heparin-induced thrombocytopenia
Warfarin-induced necrosis
Septic emboli/cholesterol emboli
2 types of non-palpable purpura
petechiae
ecchymoses
Which diseases can cause petechiae?
thrombocytopenia (idiopathic, drug-induced, thrombotic, DIC, infection)
abnormal platelet function
increased intravascular venous pressures
some inflammatory skin diseases
Which diseases can cause ecchymoses?
external trauma
DIC and infection
coagulation defects
skin weakness/fragility
Define vasculitis
inflammation of blood vessel wall
can happen in small, medium and large vessels
causes leakage of blood –> purpura
Vasculitis causes
idiopathic
infection
inflammatory + autoimmune disease
drugs
neoplastic
How is vasculitis classified?
by size of vessel
Which infections cause vasculitis?
can be any –> often after URTI
bacterial –> meningococcus
viral –> Hep B/C
Name 2 large vessel vasculitides
Giant cell (temporal) arteritis
Takayasu’s arteritis
What is GCA associated with?
polymyalgia rheumatica
GCA cutaneous involvement
rare
usually tender nodules over superficial arteries
GCA systemic manifestations
headache
jaw claudication
blindness
Who does Takayasu’s arteritis normally affect?
young women
Where does Takayasu’s arteritis affect?
vasculitis of aorta and aortic branches
Describe the early phase of Takayasu’s arteritis
pre-pulseless systemic disease
subclavian steal syndrome
anaemia
fatigue
erythema nodosum-like nodules
Describe the late phase of Takayasu’s arteritis
pulselessness with or without signs of ischaemia
hypertension
renal artery stenosis
pyoderma gangrenosum-like lesions
Name 2 medium vessel vasculitides
polyarteritis nodosa
kawasaki disease
Symptoms of polyarteritis nodosa
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
Kawasaki disease symptoms
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
Name 3 small vessel vasculitides
Henoch-schonlein purpura (IgA vasculitis)
Wegener’s granulomatosis (granulomatosis with polyangiitis)
Churg-strauss syndrome (eosinophilic granulomatosis with polyangiitis)
Who is IgA vasculitis most common in?
children <10
IgA vasculitis symptoms
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
Describe granulomatosis with polyangiitis symptoms and skin involvement
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
Describe eosinophilic granulomatosis with polyangiitis symptoms and skin involvement
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
What is the most common type of vasculitis?
cutaneous leukocytoclastic vasculitis/cutaneous small vessel vasculitis/hypersensitivity vasculitis
(same things, different names)
Describe cutaneous small vessel vasculitis
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
Vasculitis investigations (history)
History:
- associated symptoms = haematuria, haemoptysis, sinusitis, SOB/cough
- triggers = drug/infection, constitutional symptoms
Vasculitis examination findings
vital signs = pyrexial, hypertensive
distribution + description of rash - palpable?
head + neck = sinusitis, chondritis, otitis, iritis
renal = tenderness to palpation
liver = hepatosplenomegaly
pulmonary = crackles
Vasculitis investigations
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
Vasculitis treatment
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
