Today, we talked about the case of a middle-aged man with history of diabetes, HTN, and A fib who presented with acute onset of progressive painful palpable purpura on his extremities, found to be cutaneous small vessel vasculitis on skin biopsy!

Clinical Pearls

• Purpura implies problem at the level of vessel.  It can be divided into
  • Non-palpable purpura: petechiae (<3mm) or ecchymoses (>3 mm) and are usually associated with disorders of coagulation and platelets.
  • Palpable purpura: suggests inflammation and possible vasculitis.

Nomenclature:

• Cutaneous small vessel vasculitis: disease limited to skin without any systemic vasculitis or glomerulonephritis
• LCV: histopathologic term defining vasculitis of small vessels
• Hypersensitivity vasculitis: small vessel necrotizing vasculitis
• Immune complex small vessel vasculitis: associated with immune complex and/or complement deposition. If limited to skin, this is identical to cutaneous small vessel vasculitis. If not limited to skin, then other etiologies like cryo, SLE, Sjogren, RA, anti-GBM, IgA, etc.

Approach to purpura

• Hypersensitivity (in the normal complement category of vasculitis) can result from medications/drugs as well as certain conditions such as HIV.
  • Numerous meds can cause LCV including some common ones such penicillins, cephalosporins, sulfonamides (including most loop and thiazide-type diuretics), phenytoin, and allopurinol have been most often implicated

Cutaneous small vessel vasculitis:

Clinical presentation:

• Palpable purpura
• + petechiae
• Lesions can coalesce, ulcerate or be surrounded by hemorrhagic bullae
• No visceral organ involvement in CSVV. However, it can occur later in the disease course.

Diagnosis:

• Start with checking serum complement levels to guide your need for further laboratory work up!
• Skin biopsy

Management and Prognosis:

• Usually self limited and resolved within 2-4 weeks
• If uncomplicated:
  • NSAIDs
  • Antihistamines
  • Rest, elevate, compression stockings
• If complicated (presence of hemorrhagic blisters, cutaneous necrosis, or ulceration can lead to secondary infections, chronic wounds, and scarring)
  • Systemic glucocorticoids (oral steroids): pred 0.5 mg/kg of ideal body weight until new lesion formation ceases, then taper over 3-6 weeks
  • If relapse with prednisone: then colchicine or dapsone
  • If refractory: then azathioprine, methotrexate, and MMF

Example of palpable purpura with hemorrhagic blisters: