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Dysproteinemias Causing Vascular Purpura


David J. Kuter

, MD, DPhil, Harvard Medical School

Reviewed/Revised May 2023
Topic Resources

Conditions that cause an abnormal protein content in the blood, typically in the form of immunoglobulins, can affect vascular fragility and lead to purpura.

Purpura refers to purplish cutaneous or mucosal lesions caused by hemorrhage. Small lesions (< 2 mm) are termed petechiae, and large lesions are termed ecchymoses or bruises.


Amyloidosis Amyloidosis Amyloidosis is any of a group of disparate conditions characterized by extracellular deposition of insoluble fibrils composed of misaggregated proteins. These proteins may accumulate locally... read more Amyloidosis causes amyloid deposition within vessels in the skin and subcutaneous tissues, which may increase vascular fragility, causing purpura. Purpura typically occurs on the upper extremities in contrast to immune thrombocytopenia Immune Thrombocytopenia (ITP) Immune thrombocytopenia (ITP) is a bleeding disorder usually without anemia or leukopenia. Typically, it is chronic in adults, but it is usually acute and self-limited in children. Spleen size... read more Immune Thrombocytopenia (ITP) , in which purpura occurs mostly in the lower extremities. Periorbital purpura or a purpuric rash that develops in a nonthrombocytopenic patient after gentle stroking of the skin suggests amyloidosis.

Some patients with amyloidosis have macroglossia (enlarged tongue) and can have amyloid deposits on the shoulders and in the skin.

In some patients, coagulation factor X is adsorbed by amyloid and becomes deficient, but this deficiency is usually not the cause of bleeding.

Most patients have elevated levels of serum free light chains.

The diagnosis of amyloidosis is confirmed by tissue biopsy (eg, Congo red birefringence staining of affected tissue or abdominal fat pad aspirate).


Cryoglobulinemia produces immunoglobulins that precipitate when plasma is cooled (ie, cryoglobulins) while flowing through the skin and subcutaneous tissues of the extremities. Cryoglobulins may be IgG, IgM, or IgA. Mixed cryoglobulins are usually composed of IgM complexed with a monoclonal or polyclonal IgG. The immune complexes can interfere with normal platelet function and fibrin polymerization.

Cryoglobulins can also be idiopathic.

Cryoglobulinemia can also lead to small-vessel vasculitis, which can cause purpura; hyperviscosity and direct vascular trauma can contribute. Cryoglobulinemia can manifest with acral hemorrhagic necrosis, palpable purpura, livedo reticularis, and leg ulcers.

Cryoglobulins can be detected by laboratory testing.

Hypergammaglobulinemic purpura

The diagnostic finding is a polyclonal increase in IgG. Skin biopsy may be needed.

Immunoglobulin A–associated vasculitis

Palpable purpura develops mainly on the lower legs and buttocks. Because of its distribution, it can be confused with erythema nodosum Erythema Nodosum Erythema nodosum is a specific form of panniculitis characterized by tender, red or violet, palpable, subcutaneous nodules on the shins and occasionally other locations. It often occurs with... read more Erythema Nodosum , a reactive inflammatory panniculitis that can occur in patients with a variety of infectious, immunologic, neoplastic, and drug-induced disorders.

Hyperviscosity syndrome

NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
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