Imaging Studies
In vivo silver concentrations can be measured using x-ray fluorescence. [19]
Dermoscopy, reflectance confocal microscopy, and high-definition optical coherence tomography can be used in the diagnosis of generalized argyria. [20, 21]
Corneal confocal microscopy and electrophysiological tests may help confirm the diagnosis of ocular argyrosis. [22]
Histologic Findings
Small, round, brown-black granules appear singly or in clusters and are evident with routine staining. They spare both the epidermis and its appendages, appearing in greatest numbers in the basement membrane zone surrounding sweat glands. These silver granules also favor the connective-tissue sheaths around pilosebaceous structures and nerves. They have a predilection for elastic fibers and are best visualized as strikingly refractile with dark-field illumination. An increase in the amount of melanin in exposed skin also appears to occur.
Electron microscopy demonstrates electron-dense granules. In early cases, they are located within fibroblasts and macrophages, while later most are present extracellularly. Neutron activation analysis, atomic absorption spectrophotometry, or x-ray dispersive microanalysis can be used to confirm that the granules contain silver and often also sulfur and less commonly selenium. [23, 24, 25] A simpler option is to decolorize the silver by placing histologic sections into 1% potassium ferricyanide in 20% sodium thiosulfate.
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A 92-year-old asymptomatic white man with generalized argyria. For many years, this man had used nose drops containing silver. His skin biopsy showed silver deposits in the dermis, confirming the diagnosis of argyria. © Dec 3, 2008 Herbert L. Fred, MD; Hendrik A. van Dijk. Textbook content produced by Herbert L. Fred, MD; Hendrik A. van Dijk is licensed under a Creative Commons Attribution License 2.0 license.
