Primary localized cutaneous amyloidosis: a sign of immune dysregulation?

The manifestations of primary localized cutaneous amyloidosis (PLCA) are usually limited to the skin. The exact etiopathogenesis of PLCA has not been clearly elucidated yet. An increasing number of reports in the literature that associate PLCA with various autoimmune/immune disorders suggest that underlying immune-mediated factors may be implicated. We report a case of sarcoidosis and a case of IgA nephropathy in association with extensive macular amyloidosis, adding these two conditions to the list of other autoimmune/immune disorders associated with PLCA. At least a subset of PLCA patients, especially those with extensive involvement, may have associated autoimmune/immune disorders raising the possibility of a common underlying immune-mediated mechanism.