Chrysiasis revisited: a clinical and pathological study.

Chrysiasis is a distinctive and permanent pigmentation of light-exposed skin resulting from the administration of parenteral gold salts. We report a study of 40 Caucasian patients with rheumatoid arthritis, treated with intramuscular sodium aurothiomalate, of whom 31 had chrysiasis. Visible changes develop above a threshold, equivalent to 20 mg/kg gold content, and their severity depends upon cumulative dose. Focal aggregates of particulate gold are deposited in the reticular and papillary dermis in amounts that correlate with the degree of pigmentation. Characteristically, initially the periorbital region is affected by a mauve discoloration, which intensifies and deepens into a blue/slate-grey colour, while extending to involve the face, neck and upper limbs. Although chrysiasis develops insidiously and patients may be unaware of the changes, positive identification is important in order to avoid misdiagnosis and medical mismanagement, and afford appropriate reassurance. Prevention is difficult, but measures to reduce sunlight exposure may be helpful.