Secondary amyloidosis affecting the skin in arthropathic psoriasis

Cutaneous amyloidosis: a concept review

Concepts and semantics are crucial for good communication between clinicians and pathologists. Amyloidosis was described more than 150 years ago. Therefore, the terminology related to it is abundant, varied, and sometimes complex. In this report, we intend to discuss several terms related to the disease, with special emphasis on cutaneous amyloidosis. We present a review, from Virchow to present, of the concepts related to amyloidosis: its nature, the classification of cutaneous forms of the disease, and the techniques used in its diagnosis.

Secondary amyloidosis complicating psoriasis

BACKGROUND

Amyloidosis is a heterogeneous group of disorders characterized by extracellular deposition of fibrillar protein. Secondary amyloidosis occurs in patients with chronic infectious or inflammatory processes. Only 18 cases of secondary amyloidosis complicating psoriasis have been reported.

OBJECTIVE

We characterized secondary amyloidosis complicating psoriasis.

METHODS

We reviewed all cases of coexisting psoriasis and amyloidosis seen at the Mayo Clinic from 1950 to 1992. The clinical characteristics were summarized, and the literature was reviewed.

RESULTS

There were 28 cases of coexistent disease, and in five of these psoriasis was the only inflammatory condition preceding the development of secondary amyloidosis. Histopathologic confirmation with Congo red staining was available in four cases, and immunohistochemical confirmation of the characteristic amyloid A subtype was performed in two.

CONCLUSION

Follow-up of four patients supports the view that amyloidosis associated with psoriasis is an aggressive disease that may be fatal.