Adult patients with severe atopic eczema who had completed a double-blind placebo-controlled crossover trial of a specific formulation of Chinese herbal therapy were offered continued therapy for 1 year. Of 31 patients who completed the original placebo-controlled study and after a washout period and 2 months of further treatment, 17 continued treatment (group 1), 11 chose not to continue treatment (group 2), one was lost to follow-up and two patients originally in group 1 decided to stop treatment and became pregnant. At the end of the year, 12 of the patients in group 1 had greater than 90% reduction and the remaining five had greater than 60% reduction in clinical scores compared with baseline values. Clinical scores of patients in group 2 gradually deteriorated so that by the end of the year the difference between groups 1 and 2 was highly significant (P = 0.005 and P = 0.002 for erythema and surface damage, respectively). At the end of the year no patient in group 1 felt able to discontinue treatment permanently, but eight patients were on an alternate-day regimen by 6 months and remained on this regimen until the end of the year, and seven were able to control their eczema with a 1 in every 3 day treatment by the end of the year. The remaining two patients continued on daily treatments. Toxicology screening revealed no abnormalities in either full blood counts or biochemical parameters in any patient on continued treatment. Improvement in disease was not associated with any significant change in serum IgE level or peripheral blood lymphocyte subsets.(ABSTRACT TRUNCATED AT 250 WORDS)