Vasculitis is defined as an inflammation that compromises or destroys the vessel wall leading to local hemorrhagic or ischemic events. Vasculitis accounts for the presence of lower-extremity ulcers in fewer than 20 % of patients. Lower-extremity ulcers are associated with antiphospholipid antibodies, either as a manifestation of the primary antiphospholipid syndrome or secondary to the underlying connective tissue disease. Skin biopsies are gold standard for the diagnosis of cutaneous vasculitis. Cutaneous vasculitis can manifest as urticaria, infiltrative erythema, petechiae, purpura, purpuric papules, hemorrhagic vesicles and bullae, nodules, livedo racemosa, punched-out ulcers, and digital gangrene. The morphology depends on the size of the vessels and extent of the vascular bed affected. The involvement can range from a vasculitis affecting few superficial, small vessels in petechial eruptions to extensive pan-dermal small-vessel vasculitis in hemorrhagic bullae to muscular vessel vasculitis in lower-extremity nodules with livedo racemosa. Skin biopsy, with subcuticular tissue taken from the earliest, most symptomatic, reddish, or purpuric lesion, is crucial for obtaining accurate and representative diagnostic sample. Vasculitis can be classified based on the size of vessels affected and the dominant immune cell mediating the inflammation (e.g., neutrophilic, granulomatous, lymphocytic, or eosinophilic). The inflammatory process results in the disruption of small-vessel inflammatory cells with deposition of fibrin within the lumen, vessel wall coupled with nuclear debris. This picture allows the confident recognition of neutrophilic vasculitis (also known as leukocytoclastic vasculitis) involving mostly small vessels. If muscular vessels are affected by vasculitis, then one can see infiltration of its wall by inflammatory cells abundantly. Extravasation of red blood cells resulting in formation of the purpura and necrosis is usually considered to be supportive, but not diagnostic of vasculitis as they can also be seen in hemorrhagic, vaso-occlusive disorders (pseudovasculitis). Vasculitic foci associated with extravascular granulomas, tissue eosinophilia, or tissue neutrophilia signal the risk of coexistence of systemic disease. The histological information coupled with special studies (direct immunofluorescence and antineutrophil cytoplasmic data) and clinical findings prompts us more precise and accurate diagnosis of localized and systemic vasculitis syndromes (Fig. 14.2).

In patients with different types of systemic vasculitis, there can be multiple leg ulcers which are necrotic and deep. There can be atypical distribution of the vasculitis ulcerative lesions such as nail fold infarcts and splinter hemorrhages.

Patients with rheumatoid arthritis (RA) are predisposed to developing chronic leg ulcers. In one study 9 % of patients with RA had a leg ulcer at some time, and 0.6–8 % of inpatients with RA had an active leg ulcer. This compared to 1 % prevalence in the general adult population [3–5].

Clinical manifestations arise because of the systemic inflammatory response resulting from release of chemical mediators from the inflamed blood vessels. The chemical mediators give rise to nonspecific systemic manifestations. They include fever, night sweats, malaise, weight loss, arthralgia, myalgia, and laboratory features such as normocytic and normochromic anemia, leukocytosis, thrombocytosis, and raised erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). Some patients, especially early in the course of their illness, present with isolated systemic manifestations and pose a diagnostic challenge. Conversely, systemic inflammatory response is not seen in most patients with localized forms of vasculitis. More specific manifestations from involvement of various organ systems arise from one or both of the following mechanisms. Thinning of the vessel wall is seen secondary to inflammatory cell infiltration. This leads to increased vascular permeability or vessel wall rupture. Hemorrhage occurs into the affected organ.

Generally vasculitis is divided in to three groups depending on the types of vessels involved, that is: (1) large-vessel vasculitis, (2) medium-vessel vasculitis, and (3) small-vessel vasculitis (Table 14.1) [6]. Histological findings of vasculitis in different stages are dependent on the timing of biopsy. Early lesions of LCV and those of urticarial vasculitis (UV) show a sparse infiltrate of neutrophils and nuclear debris around a postcapillary venule. Mature lesions of LCV show variable amounts of fibrin and nuclear debris around a disrupted small-vessel wall. Old, waning lesions of LCV will have scant nuclear debris and fibrin deposits in and around vessels, more numerous mononuclear infiltrates, and abundant extravasated red blood cells.

There are several classification systems for vasculitis, and they include the American College of Rheumatology classification, which comprises two subcategories: (1) cutaneous small-vessel vasculitis and (2) large-vessel necrotizing vasculitis criteria. The Chapel Hill Consensus Criteria (CHCC) proposes three subcategories: (1) large-vessel vasculitis, which includes giant cell arteritis and Takayasu’s arteritis (skin lesions are uncommon); (2) medium-sized vessel vasculitis, which includes classic polyarteritis nodosa and Kawasaki’s disease (associated with mucocutaneous lymph node syndrome); and (3) small-vessel vasculitis, which encompasses Wegener’s granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis (polyarteritis), Henoch-Schönlein purpura, essential cryoglobulinemic vasculitis, and cutaneous leukocytoclastic vasculitis. Unfortunately, current vasculitis classification systems do not provide consensus for research, clinical diagnosis, and management of cutaneous vasculitis. While most practitioners appear to favor the CHCC for classifying vasculitis, there is an apparent lack of agreement of specific disorders and an overlap among primary vasculitides when the various classification systems are adopted [7].

Predisposing factors for vasculitis include infection, certain medications, and contact with allergens. A wide variety of bacterial, viral, fungal, protozoan, and helminthic organisms have been implicated in the development of vasculitis. Similarly, a wide range of medications have been implicated in causing vasculitis in some individuals, and these include insulin, penicillin, hydantoins, streptomycin, aspirin, sulfonamides, thiazides, phenothiazines, vitamins, phenylbutazone, quinine, streptokinase, tamoxifen, anti-influenza vaccine, and serum oral contraceptives. Contact with chemical agents such as insecticides, petroleum products, and food allergens (milk proteins and gluten) can also predispose susceptible individuals to vasculitis. Individuals with non-healing leg ulcers need to be referred to a specialist for appropriate diagnoses and management as vasculitis can “mimic” other disorders.

These ulcers pose a therapeutic challenge and are often resistant to treatment. Generally the ulcer wounds are taken care by adequate wound cleaning and non-sticky dressings, along with pain relief and anti-infective measures. These patients’ vasculitis ulcers usually require more attention for the pain relief.

There are five important questions to be asked when faced with a patient with possible vasculitis ulcerations depending on clinical presentation: