"Leukocytoclastic" (literally meaning 'leukocyte-destroying') refers to the damage caused by nuclear debris from infiltrating neutrophils in and around the vessels.

[6] Small fluid-filled blisters (or "vesicles"), pus-filled bumps resembling a pimple (or "pustules"), or shallow ulcers may also develop but are less common.

[6][5] The location of skin lesions varies but are most commonly found symmetrically below the waist, primarily on the buttocks and legs.

[5] In cases where a cause can be determined, medications and infectious pathogens are most common in adults, while IgA vasculitis (Henoch–Schönlein purpura) frequently affects children.

[9] Once activated, neutrophils then release preformed substances, including enzymes causing damage to vessel tissue.

[9] Evidence of this process can be seen with a sample of removed skin tissue, or biopsy, viewed under a microscope.

[10] The immune system senses these altered proteins as foreign and produces antibodies in efforts to eliminate them from the body.

[13] 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.

[13] Small vessel cutaneous vasculitis is a diagnosis of exclusion and requires ruling out systemic causes of the skin findings.

[14] Skin biopsy (punch or excisional) is the most definitive diagnostic test and should be performed with 48 hours of appearance of the vasculitis.