Argyria: A Case of Blue Lunulae

A 56-year-old male with no relevant past medical history presented to the dermatology clinic with concern of discoloration of the skin, initially noted 7 years prior and worsening. He reported no associated systemic symptoms and no relevant past medical history, including history of liver abnormalities or neurologic dysfunction. Physical exam was notable for widespread, mild diffuse gray-blue discoloration of skin, notably affecting the bilateral digital lunulae and the face, most noticeably on the pre-auricular region (Figure 1). No other pertinent physical exam findings were seen. Upon further discussion, the patient reported taking an over-the-counter colloidal silver supplement (500 ppm) regularly for the past 10 years. Given that the most favored diagnosis was argyria, nail bed biopsy was recommended for diagnostic confirmation. Punch biopsy of the nail bed of the area of discoloration was performed, and pathology showed plentiful silver granules consistent with argyria (Figure 2). The differential diagnosis for gray-blue discolored lunulae, also referred to as azure lunulae, can additionally include Wilson's disease and other medication-induced pigmentary changes. Wilson's disease is a genetic disease involving improper copper metabolism, leading to increased serum levels of copper and copper deposition in various organs [1]. While hepatic dysfunction, neurologic symptoms, and Kayser-Fleischer rings are classic findings, blue lunulae have additionally been reported [1]. Several medications in addition to silver-containing products and supplements have been implicated in pigmentary changes affecting the skin and nails, including minocycline, hydroxyurea, various chemotherapeutics, and zidovudine [2, 3]. While use of silver in Western medicine has decreased, its use in homeopathic and natural medicine for a variety of symptoms remains [4]. While not an exhaustive list, additional cases of argyria have been reported due to occupational exposures in metal-workers, in those receiving acupuncture, and on the ears of patients who wear earrings [4]. There are several types of argyria, including generalized (such as in our patient) and localized variants (such as limited to the fingers of a metal-worker or an amalgam tattoo). Due to the sunlight's effect on the chemical reaction of silver, photo-exposed areas are typically more involved [4]. Histologically, classic findings include foci of pigment within eccrine coils as well as in collagen and elastin fibers. Despite many trials, successful treatment remains challenging, although some laser modalities may be utilized [4]. This patient did not desire to pursue treatment. The recommendation was made to discontinue the silver-containing supplement. As illustrated by this case, evaluation of a patient with gray or blue skin discoloration involves thorough medical history, with particular focus on medication use as well as history of over-the-counter supplementation use. The differential diagnosis includes medication-induced pigmentary changes as well as rarer diseases such as Wilson's disease in the appropriate clinical context. In this case, given the use of a colloidal silver supplement and the lack of other systemic symptoms or pertinent medical history, the diagnosis of argyria was favored and ultimately confirmed with punch biopsy of the nail bed. While uncommon, argyria is a diagnosis that should be considered in the appropriate clinical context in patients with history of blue or gray discoloration of the skin or nail beds. The authors have nothing to report. The authors attest to obtaining written patient consent for the publication of recognizable patient photographs or other identifiable material, with the understanding that this information may be publicly available. Dr. Tolkachjov is a speaker/investigator for CASTLE Biosciences, Kerecis, Boehringer Ingelheim, Regeneron, and Bioventus/LifeNet. The authors declare no conflicts of interest. The authors have nothing to report.