Granulomatosis with polyangiitis (GPA) versus microscopic polyangiitis (MPA)
|ENT findings (sinusitis, otitis media, oral ulcers||90%||35%|
|pulmonary disease (nodules/patchy/diffuse opacities)||common||common|
|Cutaneous findings (purpura, ulceration, urticaria)||~50%||~50%|
|constitutional symptoms (fever, weight loss, anorexia)||common||common|
- GPA primarily PR3-ANCA
- MPA primarily MPO-ANCA
- 20% with GPA and MPA have the alternative ANCA, and 10% are ANCA negative
- Metal neuropathy:
- oftentimes distal symmetric sensorimotor polyneuropathy
- common causes include chronic arsenic intoxication (mining, pesticides, some homeopathic remedies/herbals), mercury (fish polluted with mercury, dentists), gold (s/p treatment with gold therapy), thallium (rodenticide, banned in US), lead (occupational exposure, lead paint, folk remedies)
Hagen et al. Diagnostic value of standardized assays for anti-neutrophil cytoplasmic antibodies in idiopathic systemic vasculitis. EC/BCR Project for ANCA Assay Standardization. Kidney Int. 1988 Mar; 53(3): 743-53.
Falk RJ, King TE. Clinical manifetations and diagnosis of granulomatosis with polyangiitis and microscopic polyangiitis. UptoDate. 2014, Jan.
Pratt RW and Weimer LH. Medication and toxin-induced peripheral neuropathy. Semin Neurol 2005 Jun; 25(2): 204-16.