The patient is typically a middle-aged adult.
Diagnostic features - all of the following:
(1) The patient has a generalized skin eruption with papules and sclerodermoid induration.
(2) The dermis shows mucin deposition, a variable proliferation of fibroblasts and collagen bands.
(3) Serum protein electropheresis shows the presence of a monoclonal gammopathy (some patients may show a polyclonal hypergammaglobulinemia).
(4) Thyroid disease (with myxedema) is absent.
Widespread skin changes are present, including:
(1) The initial finding consists of closely spaced papules, typically showing a linear arrangement.
(2) Skin induration is present.
(3) The glabella shows deep longitudinal furrows.
(4) The distal PIP joints may show the doughnut sign (central depression surrounded by a raise area).
(5) A brownish skin discoloration may develop.
(6) The eyelids may appear to be thickened.
(7) Patients may experience erythema, edema and/or pruritus.
(8) Eventually sclerotic plaques develop as papules become confluent, with sclerodactyly and reduced skin mobility.
Findings that are typically absent:
(1) telangiectasia
(2) calcinosis
(3) scalp involvement
(4) mucous membrane involvement
Organ involvement may include (often with mucin deposition in the tissues):
(1) peripheral neuropathy
(2) CNS involvement with reduced levels of consciousness
(3) renal disease
(4) esophageal disease with dysphagia
(5) restrictive lung disease and reduced diffusing capacity
(6) proximal muscle weakness
(7) arthralgias, polyarthritis or migratory arthritis
(8) laryngeal involvement
