KB, a 54-year-old previously healthy woman, was referred to the University of California, Davis, Occupational and Environmental Medicine Clinic with a 2-year history of worsening alopecia and memory loss. Her symptoms began in October 2002 with minor memory loss and fatigue. Her primary care physician conducted a thorough physical exam, which showed no abnormality; all laboratory studies (complete blood count, electrolytes, thyroid-stimulating hormone) were also normal. KB’s physician believed her symptoms were related to menopause. With no specific diagnosis or treatment recommendations, our patient started taking a variety of herbal therapies including kelp supplement, fish oil, ginkgo biloba, and grape seed extract. The kelp supplement was the only herbal therapy taken regularly throughout the course of her illness. She initially took two tablets of Icelandic Kelp supplement (Liminaria digitata) per day (41 mg kelp, 66 mg calcium, 225 μg iodine). Over the next few months, she subjectively noticed new and progressively worsening symptoms. During her exam, it was noted that her short- and long-term memory had become impaired to the point where she could no longer remember her home address, a location where she had lived for the previous 5 years. She also began having difficulties functioning at work, where she did intake for a mental health facility.
KB’s gynecologist believed her symptoms were likely due to a relative estrogen deficiency and adjusted her estrogen dose. This resulted in no change in symptoms. Ancillary testing included a brain magnetic resonance image showing nonspecific changes. Further complete blood count, chemistry panel, and thyroid studies were also normal. Still lacking a clear diagnosis, KB decided to increase her daily kelp supplementation to at least four pills per day. At this point, she first noticed gastrointestinal (GI) symptoms including diarrhea, nausea, and vomiting without hematemesis. She developed daily pressure headaches as if “there was a band around her head.” Additionally, she became excessively weak and fatigued as the day progressed, requiring more sleep than previously. By the summer of 2003, she noticed a lacy, erythematous rash on her lower legs bilaterally. Other dermatologic findings included onchyolysis. Physical findings were confirmed on dermatologic assessment, which yielded a diagnosis of onchomycosis. An antifungal was prescribed but was of no benefit to her condition. By the summer of 2003, the debilitating nature of her symptoms forced her to leave her full-time job and take part-time work.
Her physician believed that her symptoms resembled those of a patient he had previously seen with arsenic toxicity. On 9 October 2003, a spot urine sample showed an arsenic concentration of 83.6 μg/g creatinine (normal < 50 μg/g creatinine). No lead or mercury was detected.
A detailed exposure history focusing on potential sources of arsenic was conducted. KB’s home water is from a deep well that was found to contain arsenic below detectable levels. Her diet consisted of less than one serving of seafood/fish per week. A sample of the kelp supplement was analyzed by Columbia Analytic Services (Kelso, WA) and showed an arsenic concentration of 8.5 mg/kg. No arsenic was detected in the fish oil she had been taking. The ginkgo biloba and grape seed extract were not analyzed.
Given the arsenic contamination in the kelp supplement, her physician recommended that she stop taking the supplement. She noted a dramatic improvement in her neurologic, GI, and dermatologic symptoms. Three weeks after stopping supplement use, KB returned to full-time work on 1 November 2003, with nearly complete resolution of symptoms. Repeat spot urine arsenic on 10 December 2003, was 25 μg/L (normal 0–50 μg/L), down over one-third from 2 months before. In a urine sample analyzed on 26 February 2004, arsenic was undetectable. Blood arsenic on 26 February 2004, was 8 μg/L (normal for reporting laboratory, 2–23).