Vasculitis mimickers
Large Vessel
aortitis + aneurysms
1. Infections
I) Bacterial
• Syphilis: tertiary phase (after 20 years of disease progression). No
involvement of the abdominal aorta (hypothesized that the absence of vasa vasorum in the
abdominal aorta may explain the specific tropism of syphilis for the thoracic aorta). Fusiform
aneurysm [ατρακτοειδές= σ’ όλες τις πλευρές του αγγείου].
• Streptococcus / Staphylococcus
• Salmonella (non-typhoid)
• TB
• Coxiella (Q-fever): the diagnosis is difficult because the positive serology
may be related to an old infection, unrelated to the aortic involvement. The study of
antibody avidity can help date the infection (low avidity = recent infection). Treatment: HCQ
(600mg) + doxycycline for 2 years.
• Rickettsia (Rocky mountain fever): infects vascular endothelial cells.
• Whipple
II) Fungal: Histoplasma, Aspergillus
III) Viral
• VZV (can mimic cranial GCA, granulomatous aortitis and cause
intracerebral VZV vasculopathy). VZV is the only human virus that has been shown to
replicate in arteries and produce vasculopathy.
• SARS-CoV2 (during the viremic phase, the virions attack directly the
vascular endothelium, with highly expressed ACE-2 receptors)
2. Collagen diseases
Marfan, vascular Ehlers-Danlos, Loeys-Dietz, Neurofibromatosis-1, Alport
3. Inflammatory
• IgG4-RD
i) periaortitis (20-36%) that affects more the abdominal aorta and the sub-renal part.
ii) aortitis (8%) that affects more the thoracic aorta and leads to aneurysms.
GCA shows more intense and diffuse vascular involvement and a higher
frequency of carotid, subclavian, axillary artery involvement than IgG4-RD and not so often
sub-renal. IgG4-RD can also involve the temporal arteries, although in most cases it is peri-
arteritis and not transmural arteritis, as is in GCA.
• Behçet: aneurysms / stenosis in aorta, pulmonary arteries, femoral arteries […]
• Cogan
• RP / VEXAS
• sarcoidosis
• AS (root of aorta)
• AAV: GPA may lead to lymphocytoplasmic infiltrates within the temporal artery (also
stenosis?) and cause severe headaches mimicking GCA (from affecting the vasa vasorum?)].
4. Histiocytosis: Erdheim-Chester
, 5. Atherosclerosis: usually lower limbs, aorta, carotids, eccentric, focal lesions, at
bifurcation sites. On PET/CT: irregular, focal appearance ≠ LVV: homogenous, longitudinal,
linear.
6. Drug-induced: immune checkpoint inhibitors, G-CSF.
Medium vessel
livedo, ulcers, digital gangrene, microaneurysms, mononeuritis multiplex
Microaneurysms / stenosis
•Atherosclerosis
•Segmental arterial mediolysis: non-inflammatory, non-atherosclerotic
vasculopathy, mostly in abdominal arteries, known to produce spontaneous hemorrhage
into the mesentery. Male predominance >60yrs with abdominal pain. Biopsy: segmental
mediolysis and linear fibrin deposit between media and adventitia →thickening. Imaging:
stenosis, aneurysm, dissection, occlusion of mostly abdominal arteries. Treatment:
conservative, blood pressure regulation, analgesics. (SAM: Άντρες - Abdominal - Aorta).
•Fibromuscular dysplasia: female predominance, >50yrs and it affects mostly renal,
extracranial carotids and vertebral arteries →early onset / resistant HTN (if renal arteries),
bruits, aneurysms, headache, TIA/stroke (if carotids). Treatment: conservative, endovascular
therapy/surgery for complications.
•Marfan, vascular Ehlers-Danlos
•Infections: bacterial, TB, fungal, syphilis, Lyme, septic emboli, HIV
•Drugs: cocaine, MDMA (both probably due to severe hypertension episodes and
the direct endothelial damage caused by vasoconstriction)
Livedo racemosa: aPS, livedoid vasculopathy (venous stasis, autoimmune, thrombophilia,
neoplasia), Sneddon (stroke + livedo, thrombosis, can be aPL [+]),PAN, DADA2, essential
thrombocythemia, polycythemia vera, TAO.
Ulcers: venous insufficiency, diabetic foot, atherosclerosis, aPS, livedoid vasculopathy,
calciphylaxis, cryo-vasc, PAN, DADA2, pyoderma gangrenosum.
Calciphylaxis: small and medium-size vascular, skin, subcutaneous fat deposits of
calcium oxalate crystals leading to ischemia, necrosis, painful skin ulcers, acrocyanosis and
livedo reticularis, in patients with CKD.
Emboli: cholesterol emboli, atrial myxoma, aPS, endocarditis.
For brain
•Moyamoya: progressive stenosis/occlusion of the intracranial internal carotid
arteries and their major branches (especially the anterior and middle cerebral arteries),
leading to the development of fragile collateral vessels at the base of the brain that appear
like a "puff of smoke" on cerebral angiography (which is what "moyamoya" means in
Japanese).
•MELAS (mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes)
•CADASIL (cerebral autosomal-dominant arteriopathy with subcortical infarcts and
leukoencephalopathy)
•DADA2
•Susac
Coronary artery ectasias / aneurisms
•Atherosclerosis
Large Vessel
aortitis + aneurysms
1. Infections
I) Bacterial
• Syphilis: tertiary phase (after 20 years of disease progression). No
involvement of the abdominal aorta (hypothesized that the absence of vasa vasorum in the
abdominal aorta may explain the specific tropism of syphilis for the thoracic aorta). Fusiform
aneurysm [ατρακτοειδές= σ’ όλες τις πλευρές του αγγείου].
• Streptococcus / Staphylococcus
• Salmonella (non-typhoid)
• TB
• Coxiella (Q-fever): the diagnosis is difficult because the positive serology
may be related to an old infection, unrelated to the aortic involvement. The study of
antibody avidity can help date the infection (low avidity = recent infection). Treatment: HCQ
(600mg) + doxycycline for 2 years.
• Rickettsia (Rocky mountain fever): infects vascular endothelial cells.
• Whipple
II) Fungal: Histoplasma, Aspergillus
III) Viral
• VZV (can mimic cranial GCA, granulomatous aortitis and cause
intracerebral VZV vasculopathy). VZV is the only human virus that has been shown to
replicate in arteries and produce vasculopathy.
• SARS-CoV2 (during the viremic phase, the virions attack directly the
vascular endothelium, with highly expressed ACE-2 receptors)
2. Collagen diseases
Marfan, vascular Ehlers-Danlos, Loeys-Dietz, Neurofibromatosis-1, Alport
3. Inflammatory
• IgG4-RD
i) periaortitis (20-36%) that affects more the abdominal aorta and the sub-renal part.
ii) aortitis (8%) that affects more the thoracic aorta and leads to aneurysms.
GCA shows more intense and diffuse vascular involvement and a higher
frequency of carotid, subclavian, axillary artery involvement than IgG4-RD and not so often
sub-renal. IgG4-RD can also involve the temporal arteries, although in most cases it is peri-
arteritis and not transmural arteritis, as is in GCA.
• Behçet: aneurysms / stenosis in aorta, pulmonary arteries, femoral arteries […]
• Cogan
• RP / VEXAS
• sarcoidosis
• AS (root of aorta)
• AAV: GPA may lead to lymphocytoplasmic infiltrates within the temporal artery (also
stenosis?) and cause severe headaches mimicking GCA (from affecting the vasa vasorum?)].
4. Histiocytosis: Erdheim-Chester
, 5. Atherosclerosis: usually lower limbs, aorta, carotids, eccentric, focal lesions, at
bifurcation sites. On PET/CT: irregular, focal appearance ≠ LVV: homogenous, longitudinal,
linear.
6. Drug-induced: immune checkpoint inhibitors, G-CSF.
Medium vessel
livedo, ulcers, digital gangrene, microaneurysms, mononeuritis multiplex
Microaneurysms / stenosis
•Atherosclerosis
•Segmental arterial mediolysis: non-inflammatory, non-atherosclerotic
vasculopathy, mostly in abdominal arteries, known to produce spontaneous hemorrhage
into the mesentery. Male predominance >60yrs with abdominal pain. Biopsy: segmental
mediolysis and linear fibrin deposit between media and adventitia →thickening. Imaging:
stenosis, aneurysm, dissection, occlusion of mostly abdominal arteries. Treatment:
conservative, blood pressure regulation, analgesics. (SAM: Άντρες - Abdominal - Aorta).
•Fibromuscular dysplasia: female predominance, >50yrs and it affects mostly renal,
extracranial carotids and vertebral arteries →early onset / resistant HTN (if renal arteries),
bruits, aneurysms, headache, TIA/stroke (if carotids). Treatment: conservative, endovascular
therapy/surgery for complications.
•Marfan, vascular Ehlers-Danlos
•Infections: bacterial, TB, fungal, syphilis, Lyme, septic emboli, HIV
•Drugs: cocaine, MDMA (both probably due to severe hypertension episodes and
the direct endothelial damage caused by vasoconstriction)
Livedo racemosa: aPS, livedoid vasculopathy (venous stasis, autoimmune, thrombophilia,
neoplasia), Sneddon (stroke + livedo, thrombosis, can be aPL [+]),PAN, DADA2, essential
thrombocythemia, polycythemia vera, TAO.
Ulcers: venous insufficiency, diabetic foot, atherosclerosis, aPS, livedoid vasculopathy,
calciphylaxis, cryo-vasc, PAN, DADA2, pyoderma gangrenosum.
Calciphylaxis: small and medium-size vascular, skin, subcutaneous fat deposits of
calcium oxalate crystals leading to ischemia, necrosis, painful skin ulcers, acrocyanosis and
livedo reticularis, in patients with CKD.
Emboli: cholesterol emboli, atrial myxoma, aPS, endocarditis.
For brain
•Moyamoya: progressive stenosis/occlusion of the intracranial internal carotid
arteries and their major branches (especially the anterior and middle cerebral arteries),
leading to the development of fragile collateral vessels at the base of the brain that appear
like a "puff of smoke" on cerebral angiography (which is what "moyamoya" means in
Japanese).
•MELAS (mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes)
•CADASIL (cerebral autosomal-dominant arteriopathy with subcortical infarcts and
leukoencephalopathy)
•DADA2
•Susac
Coronary artery ectasias / aneurisms
•Atherosclerosis
