PracticeUpdate Dermatology May 2019

CONFERENCE COVERAGE 22

American Academy of Dermatology Annual Meeting 2019 1–5 MARCH 2019 • WASHINGTON DC • USA

Courtesy of the AAD

Dr. InYoung Kim's Take-Aways By InYoung Kim MD, PhD

Vasculitis – Robert Micheletti, University of Pennsylvania

Additional indiscriminate work-up is unlikely to be helpful, including ESR/CRP (often abnormal), ANCA and SPEP (rarely abnormal), chest x-ray, CT, angiography (rarely positive, with poor sensitivity). ― ― Let the review of systems guide the work-up! Get a fecal occult blood test in patients with abdominal pain or gas- trointestinal bleeding; a chest x-ray or chest CT if there is cough or dyspnea; autoimmune work-up if there is joint pain, fatigue, etc. ― ― If skin lesions are suggestive of medium (or small to medium) vessel vasculitis (eg, retiform purpura), do a work-up for appropriate conditions such as cryoglobulinemia, adeno-as- sociated virus, polyarteritis nodosa. • For those with concerning symptoms or chronic/recurrent lesions, a reasonable work-up includes: ― ― CBC, BMP, urinalysis, and liver function tests; infectious serologies, including hepatitis B and C, HIV, antistreptolysin O; rheumatologic work-up, including antinuclear antibodies and rheumatoid factor (which screens for rheumatoid arthritis and is a surrogate for mixed cryoglobulins)

Small-vessel vasculitis Biopsy

• Always biopsy, as even the most astute clinician can be fooled by mimickers – generalized capillaritis, bug bites, actinic purpura, livedoid vasculopathy, viral exanthem. • Lesions are dynamic – timing and location of biopsy are critical. Choose well-established, but not old, lesions (ideally, 1–2 days old). • Tissue eosinophilia may suggest drug-in- duced vasculitis. • Depth or severity of inflammation may predict systemic involvement or even underlying malignancy. Work-up • The single most important initial lab to order in the setting of vasculitis is urinalysis with micro to rule out kidney involvement • For an initial episode of straightforward vasculitis with a negative review of sys- tems, nothing more than a CBC, BMP, and urinalysis (with micro) may be required.

PRACTICEUPDATE DERMATOLOGY