Erythema elevatum dilutinum

• rare localised cutaneous vasculitis in adults
• idiopathic but may occasionaly occur in hepatitis, HIV or haematological malignancy (1)
  • other possible associations include (2) previous infection particularly by streptococcus or it can be a manifestation of occult neoplasia, including myeloma, myelodysplasia, or acute myelogenous leukaemia, and nonneoplastic disorders such as inflammatory bowel disease, relapsing polychondritis, and rheumatoid arthritis
  • there is no association with systemic vasculitis, and autoantibodies are not usually detected
• red-purple plaques occur on the back of hands and joints; these plaques gradually harden and become yellow-brown
• histology - leukocytoclasis with fibrosis and granuloma formation
  • even when the clinical course is chronic, the histological picture is acute (2) Microscopic features include angiocentric neutrophils with some leucocytoclasis, but fibrin is scanty
    • infiltrate is often mixed with some lipid-containing histiocytes
    • laminated angiocentric fibrosis again may be present.
• treatment - dapsone treatment (1)

Reference:

• (1) Dermatology in Practice (2003), 11(4), 14-18.
• (2) Davies DJ. Small vessel vasculitis. Cardiovascular Pathology 2005; 14 (6): 335-346.