Severe Acute Radiation Dermatitis in a Patient with Argyria

Argyria is a rare cutaneous condition due to dermal silver deposition leading to irreversible blue-grey discoloration. Acute radiation dermatitis (RD) is an expected toxicity in patients undergoing radiotherapy but it is unknown to what extent argyria affects the onset and severity of RD. We report a patient with argyria treated with concurrent chemoradiotherapy for Merkel cell carcinoma who experienced an unexpectedly brisk and severe RD during treatment. Possible mechanisms for this interaction are considered. 1. Introduction The Therapeutic Goods Administration of Australia has not approved colloidal silver products for therapeutic usage [1]. However, complementary and alternative medicine practitioners may promote colloidal silver tonic for unsubstantiated antineoplastic, antibiotic, or antiviral effects and products labelled as dietary supplements are available in Australia. Chronic use may be associated with neurological, renal, and skin toxicities [2]. Argyria is a condition where irreversible deposition of colloidal silver occurs in the dermis leading to variable blue or slate-grey discoloration. Diagnosis is usually made clinically but silver granules can be seen on skin biopsy as characteristic brown or black granules arranged in single file or clusters surrounding pilosebaceous structures and nerve fibres. The effect of the presence of argyria on the tolerance of the skin to therapeutic radiotherapy (RT) is not known. Merkel cell carcinoma (MCC) is a rare cutaneous neuroendocrine malignancy with a high propensity for locoregional and distant recurrence. Following wide local excision, adjuvant radiotherapy to the primary site, locoregional nodes, and intervening dermal lymphatics is indicated in most cases [3]. We report on a patient with established generalized argyria who underwent postoperative RT with concurrent chemotherapy for MCC of the head and neck region and developed an unexpectedly brisk and severe skin reaction during treatment. We characterise the reaction and consider whether the presence of argyria may have enhanced his sensitivity to treatment. 2. Case Report A fit 75-year-old man was referred to our institution with a rapidly enlarging violaceous nodule localised to the right temple associated with bleeding but no pain or formication. The patient admitted to using colloidal silver in the preceding ten months for general wellbeing, and clinically there was evidence of generalised argyria. No information was available on dose or formulation because he prepared the solution himself. He underwent wide local excision of the right