amyloidosis—primary localised cutaneous—1
A hereditary condition (OMIM:105250) characterised by localised amyloid deposition in the skin, which typically presents with itching, hyperpigmentation and thickening/lichenification–especially of the lower legs, which may be exacerbated by itching and rubbing. The deposits consist of keratin filaments, serum amyloid P component, and immunoglobulins.
Molecular pathology Defects of OSMR, that encodes oncostatin M receptor, which associates with IL31RA to form the IL31 receptor, cause amyloidosis—primary localised cutaneous—1.
Synonyms Amyloidosis—familial cutaneous lichen, amyloidosis IX, amyloidosis—primary cutaneous—1, familial cutaneous lichen amyloidosis, familial lichen amyloidosis, lichen amyloidosis familal, PCA, PLCA1