Micrograph of<unk> . The section shows all features of leucocytoclastic vasculitis. A mixed inflammatory cell population surrounding the postcapillary venules of the superficial dermis. The infiltrate consists of neutrophils with nuclear dust (dashed arrows) and shows high affinity for the<unk> s. Features of vascular injury are shown including fibrinoid necrosis (asterisks) and erythrocyte extravasation (solid arrows). The diagnostic testing for vasculitis should be guided by the patient's history and physical exam. The clinician should ask about the duration, onset, and presence any associated symptoms such as weight loss or fatigue (that would indicate a systemic cause). It is important to distinguish between IgA and non-IgA vasculitis. IgA vasculitis is more likely to present with abdominal pain, bloody urine, and joint pain. In the case that the cause is not obvious, a reasonable initial workup would include a complete blood count, urinalysis, basic metabolic panel, fecal occult blood testing, erythrocyte sedimentation rate (ESR), and C-reactive protein level.<unk><unk>  cutaneous vasculitis is a diagnosis of exclusion and requires ruling out systemic causes of the skin findings. Skin biopsy (punch or excisional) is the most definitive diagnostic test and should be performed with 48 hours of appearance of the vasculitis. A skin biopsy will be able to determine if the clinical findings are truly due to a vasculitis or due to some other cause. Classification Subtypes of<unk><unk>  vasculitis include: :* IgA vasculitis (Henoch-Schönlein purpura) :* Acute hemorrhagic edema of infancy :* Urticarial vasculitis :* Cryoglobulinemic vasculitis :* Erythema elevatum diutinum :* Granuloma faciale :* ANCA-associated vasculitis :* Arthropod bites :* Platelet dysfunction or deficiency :* Cholesterol emboli :* Septic emboli :* Livedoid vasculopathy
Cutaneous small-vessel vasculitis
Livedoid vasculitis
Urticarial vasculitis
Systemic vasculitis
Acute cutaneous lupus erythematosus
Bullous small vessel vasculitis
Subacute cutaneous lupus erythematosus
Poikiloderma vasculare atrophicans