Strange Case of Man Whose Skin Turned Gray Remains a Mystery

Presenting to a Hong Kong hospital with complications from a urinary flow obstruction, an 84-year-old man left clinicians perplexed over a seemingly unrelated grayness to his skin, eyes, and nails.

The unusual color was far from new. In fact, his faint ashen hue reportedly appeared a whole five years prior.

Blood tests soon revealed the culprit – silver. At concentrations more than 40 times that found in most individuals, the man's body was positively saturated with the metal, causing it to bead into tiny oxidized granules just beneath his skin in the membranes of his sweat glands, blood vessels, and dermal fibers.

Buildup of silver granules in the basement membrane of sweat glands. (Lee et al., NEJM, 2024)

Known as argyria, the systemic buildup of silver in body tissues is rare, but far from unknown. In extreme cases individuals can be left with large areas of exposed skin that appear strikingly blue.

Historically the condition affected artisans and miners who worked closely with the metal, yet in a number of cases the element was absorbed from medications that incorporated silver for its antimicrobial properties.

Colloidal silver continues to be used without scientific evidence supporting its efficacy, with the US Food and Drug Administration warning the ingredient is not currently considered a safe or effective means of treating any disease or condition.

That isn't to say 'treatments' based on silver aren't readily available around the world, often marketed as dietary supplements that claim to help expel toxins or aid the body's defenses.

The metal is commonly absorbed internally through the lungs, skin, or digestive system as a charged particle, depositing far and wide as it is transported throughout the body. Wherever UV radiation from sunlight can reach, the silver ions can catch an electron and transform into a form that can react to form compounds that reflect a dull gray or blue color.

As the recently published case study reports, the 84-year-old was being treated for a benign prostate tumor, though his only medication was a common antiandrogen called finasteride, which ought to contain nothing even remotely like silver.

Having worked for years as a waiter, the patient offered no obvious source of silver contamination in his workplace. Without any of his neighbors presenting with similar changes in skin color, exposure in his home environment was also unlikely.

Fortunately the condition is unlikely to have a significant impact on the patient's long-term health. Aside from the subtle cosmetic effects, silver buildup is relatively benign at all but the highest of concentrations, at most potentially affecting the absorption of some antibiotics and drugs such as thyroxine.

That said, the man would have a hard time getting rid of his slate-gray tone if he wanted to. Currently there are no known measures that can eliminate a buildup of silver from the body.

Just where it came from remains a mystery, for now. With a diagnosis in his medical record, however, the patient's physicians will no doubt keep a close eye on his silver status for years to come.

This case study was published in The New England Journal of Medicine.