Page 419 - The Vasculitides, Volume 1: General Considerations and Systemic Vasculitis

Dermatologic Aspects of Systemic Vasculitis 393

The distinction between localized cutaneous and systemic vasculitis is important since
the former carries a relatively favorable outcome, while the latter conveys the likelihood of
permanent organ damage, increased morbidity and mortality. About 20% to 40% of patients
with cutaneous vasculitis have concomitant limited systemic vasculitis notably kidney such as
so called renal-dermal vasculitis while the likelihood of chronicity and systemic progression
is enhanced when there is coexisting CTD, cryoglobulinemia, frank ulceration [69], arthralgia
[16], more than one form of cutaneous vasculitic lesion such as ulceration and palpable
purpura, putative muscular and SVV, normal serum IgA levels [14], paresthesia, fever,
painless lesions [16] and cutaneous necrosis [70]. Histologically, the severity of vessel injury
in cutaneous vasculitis correlates with the clinical severity and course [69, 71]. Others have
noted histopathological changes of LCV were not predictive of extracutaneous involvement
[72]. Lesional IgA deposits by DIF predict proteinuria and subsequent renal involvement
[73]. Up to 60% of patients presenting with cutaneous vasculitis on skin biopsy have SVV
restricted to the dermis while the remainder have deep dermal and pannicular SVV and
muscular vessel involvement [74].

Therapy

Therapy depends upon the nature and severity of the vasculitis. Mild hypersensitivity due
to drug reactions should be treated with discontinuation of the offending agents,
antihistamines for urticaria-associated pruritus, and a short course of corticosteroids in more
severe cases. Simple observation may be adequate for mild cases and transient lesions of
HSP/IgAV-related purpura. Non-steroidal anti-inflammatory agents, colchicine,
antihistamines, and dapsone may be employed in chronic cutaneous vasculitis without
recognizable cause and in selected patients prior to administration of corticosteroids and
cytotoxic drugs. Rituximab has equivalent remission-induction efficacy as cyclophosphamide
in AAV each in conjunction with corticosteroids. Morphologic alternations of the vessel
walls, lumina, and perivascular areas may be useful in treatment strategy. Healed arteritis
with intimal thickening due to luminal occlusion should suggest the need for anticoagulation
and vascular dilating agents, whereas pathologically confirmed acute and subacute arteritis
generally warrants combination immunosuppressive therapy to suppress ongoing vascular
inflammation and tissue damage.

References

[1] Carlson JA, Ng BT, Chen KR. Cutaneous vasculitis update: diagnostic criteria,
classification, epidemiology, etiology, pathogenesis, evaluation and prognosis. Am. J.
Dermatopathol. 2005; 27:504-528.

[2] Carlson JA. The histological assessment of cutaneous vasculitis. Histopathology 2010;
56:3-23.

[3] Braverman IM. The cutaneous microcirculation. J. Investig. Dermatol. Symp. Proc.
2000; 5:3-9.

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