Polyarteritis Nodosa (PAN)

  • Multisystem segmental necrotizing vasculitis of medium-sized vessels; cutaneous PAN (variant) limited to skin
  • Cutaneous findings include ‘punched out’ ulcers, livedo reticularis, subcutaneous nodules, and acral gangrene
  • Association: inflammatory disease (IBD, SLE) or infection (HBV, strep)
   
 
Table 3-23 Vaso-Occlusive Diseases
 EntityClinical FindingsHistology/Treatment
 
Livedoid vasculopathy
(Atrophie blanche)
Painful ulcerations on lower legs ± with surrounding livedo reticularis → heal with atrophic hypopigmented scars (atrophie blanche)
Histology: superficial dermal vessels with hyalinized walls, thrombi, mild perivascular infiltrate

Treatment: antiplatelet, anticoagulant and fibrinocytic therapies
 
Cholesterol emboli
(Figure 3.45E)
Findings include livedo reticularis, peripheral gangrene, ulceration, nodules, cyanosis, retiform purpura
Histology: elongated cholesterol clefts within small vessels, thrombi

Treatment: supportive treatment, ± antiplatelet agents
 
Anti-phospholipid
syndrome (APS)
(Figure 3.45D)
Findings include livedo reticularis, Raynaud’s phenomenon, vasculitis-like lesions, splinter hemorrhages


{Labs: anti-β2 glycoprotein, lupus anticoagulant, anti-cardiolipin antibodies}
Histology: noninflammatory small vessel thombosis

Treatment: anticoagulation, antiplatelet agents
 
Sneddon’s syndrome
Persistent livedo reticularis associated with systemic arterial thrombi; labile hypertension, recurrent neurologic symptoms


{Can be manifestation of APS or distinct entity (skin/brain only)}
Histology: partial or complete occlusion of small vessels

Treatment: warfarin
 
Malignant atrophic
papulosis
(Degos disease)
(Figure 3.45F)
Crops of small erythematous papules → porcelain white scars (similar to atrophie blanche); GI and CNS symptoms
Histology: wedge-shaped dermal infarct, thrombosed arteriole (typically in subcutaneous fat)

Treatment; no proven treatment; aspirin ± pentoxifylline