Arsenic-induced skin changes generally result from chronic arsenic exposure and have a latency of several years. Hyperpigmentation typically precedes hyperkeratoses, which in turn precede dermal neoplasms. The presence of both hyperpigmentation and palmar-plantar keratoses in the patient suggests that his arsenic exposure began at least 3 years ago, before consumption of drinking water from his current well. Since he resided on nearby property for 10 years, the well at that location should also be suspected of containing high levels of arsenic.
The patient’s wife, who resides with the patient and may consume the same well water, is at risk for chronic arsenic poisoning. Residents in the surrounding geographical area, who may also be obtaining water from artesian wells should be considered at risk. Former area residents who consumed arsenic chronically before moving away constitute a third group potentially at risk for delayed development of arsenic-associated disease.
A careful history reveals that the wife, unlike the patient, consumed the well water infrequently, preferring instead to drink bottled soft drinks and juices. Before moving with her husband 10 months ago, she resided in a metropolitan area geographically remote from the present site, where the water was not obtained from wells. Thus, because her arsenic ingestion was markedly lower and of shorter duration than her husband’s, she has not yet developed signs or symptoms of chronic arsenic intoxication.
Both the patient and his wife use the arsenic-containing well water for showers and baths. The substantial amount of arsenic in the wife’s hair likely reflects external contamination from this source. The arsenic content of the husband’s hair is elevated from a combination of external contamination and internal incorporation into the growing hair. The relative contribution from endogenous and exogenous sources cannot be distinguished through bulk hair analysis.
Immediate cessation of consumption of arsenic-containing well water is the essential first step. Because the utility of chelating agents in reversing or improving the patient’s arsenic-related peripheral neuropathy, anemia, and palmar-plantar keratoses is unestablished, chelation treatment cannot be routinely recommended. Analgesics and/or certain tricyclic antidepressants have been reported to be beneficial for the painful dysesthesias associated with peripheral neuropathies. Because some reports indicate that vitamin A analogs (retinoids) may be valuable in the treatment of precancerous arsenical keratoses, referral to a dermatologist for consideration of this treatment is indicated. The patient will remain at risk for the delayed appearance of arsenic-related skin cancer and merits regular, long-term dermatologic follow-up.
Because of the likelihood that other wells in the area contain elevated levels of arsenic, public health intervention may be necessary to prevent other cases of hazardous arsenic exposure.
More information on the adverse effects of arsenic and the treatment and managment of arsenic-exposed persons can be obtained from ATSDR, your state and local health departments, poison control centers, and university medical centers. Case Studies in Environmental Medicine: Arsenic Toxicity is one of a series. To obtain other publications in this series, please use the order form on the inside back cover. For clinical inquiries, contact ATSDR, Division of Health Education, Office of the Director, at (404) 639–6204.