cutaneous small vessel vasculitis (LCV)

Question 1

Pathogenesis of LCV:

Answer 1

Antigen is bound by antibodies, forms immune complexes that deposit into post-capillary venues→ activation of complement→inflammation of vessels

Question 2

Triggers of LCV:

Answer 2

MANIC:

Medications: beta lactams, bactrim, thiazides, OCPs

Autoimmune CTD: Lupus, RA, sjogren’s

NSAIDS

Infections and IBD: group A strep, hepatitis, HIV, candida

Cancer: leukemias and solid organ cancers

Question 3

Clinical presentation of LCV:

Answer 3

petechiae and palpable purport on lower extremities that present 1-2 weeks after a trigger (or 6 months after autoimmune disease or cancer)

• may be itchy or painful or asymptomatic

Question 4

How long after trigger does LCV typically present?

Answer 4

1-2 weeks, or 6 months for autoimmune or cancer trigger

Question 5

What is the clinical course of LCV?

Answer 5

typically resolves over several weeks (but PIH can last for months to year)

Question 6

Histology of LCV:

Answer 6

Question 7

Lab workup for small vessel vasculitides:

Answer 7

if no concern for systemic involvement:

• CBC, BMP, ESR, LFTs, UA

If concern for systemic involvement:

• GI: stool guiaiac
• Renal: serial UAs
• Infectious: Hep panel, HIV
• Inflammatory: ESR/CRP, ANA, complement levels
• Neoplastic: SPEP/UPEP

Question 8

What questions to ask to screen for systemic involvement in small vessel vasculitides?

Answer 8

do a full ROS!!!

• GI, renal, joints, fevers, myalgia, weight loss, infections