Apparent poisoning by wood preservatives: an attributional syndrome.

Recent reports have pointed to an increased number of patients presenting with multisystem symptoms which they attribute to chemical exposures or to heightened chemical sensitivity. Twenty patients exposed to wood preservative products, who attended a joint toxicology and psychiatric clinic, were reviewed by a retrospective case note analysis. Thirteen patients attributed their symptoms to the wood preservative soon after the exposure, and seven patients developed the attribution only at a later date. Reported symptoms referred to all body systems, but there were few physical signs. Clinical findings suggest that the acute symptoms were consistent with the expected toxic effects, but the chronic symptoms could not be explained physically. Patient's beliefs about chemical poisoning could be understood as arising in the context of an attributional process, representing a sociopsychosomatic syndrome precipitated by wood preservative exposure. Patient management included a discussion of findings from assessments, published information, along with counseling where appropriate. Follow-up information from their general practitioners indicated a possible improvement in 50% of patients.

Possible association of liver damage with the use of Chinese herbal medicine for skin disease.

From January 1991 to December 1993, we received reports of 11 cases of liver damage following the use of Chinese Herbal Medicine (CHM) for skin conditions. There was strong evidence of an etological association in 2 cases in which recovery after dechallenge and recurrence of hepatitis after rechallenge were observed. The time-course relationship, recovery after ceasing CHM, and absence of alternative causes of liver damage suggested an association in 2 further symptomatic cases following a single period of exposure. Herbal material was available for analysis in 7 cases. The plant mixtures varied so no single ingredient could account for liver injury in this case series. The mechanism of toxicity is unclear; effects do not appear dose-related and are probably idiosyncratic. Liver function should be monitored in patients who use CHM for skin disorders and its use discontinued if problems occur. The complexity of these cases illustrates the requirement for continuous surveillance of CHM including pharmacognostical investigation of ingredients.

Toxicological problems resulting from exposure to traditional remedies and food supplements.

The National Poisons Unit, London, carried out a pilot survey to investigate the frequency and severity of adverse effects/toxicity from exposure to traditional medicines and food supplements reported to the Unit. Enquiries related to suspected poisoning events were reviewed retrospectively from January 1983 to March 1989, and prospectively in 1991. Further information about cases identified by the prospective review was obtained, when appropriate, by follow-up questionnaire, clinical consultation by a consultant toxicologist, toxicological analyses of samples from patients and from products, and botanical identification of dried plant material. In total, 5536 enquiries were identified. Symptoms were reported in 657 (12%) of these. There was a large number of reports of accidental ingestion of vitamin preparations by children under 5 years. Appropriate assessment was possible in only relatively few cases, due to insufficient documentation, and poor labelling of certain products. A probable link between exposure and adverse effects was identified in 42 cases, and was highly probable in two. Heavy metal poisoning resulting from use of contaminated traditional remedies was confirmed in 5 cases. There was evidence that some patients took excessive doses of food supplements, without realising that this might result in toxic effects. The results of this pilot study suggest that there is a need for further surveillance to provide an appropriate risk assessment of food supplements and herbal remedies, improved quality control and labelling of these products, and increased awareness of their potential hazard.