Routine patch testing with cadmium chloride

During a 22-month period, 2.0% cadmium chloride in distilled water was included in our routine patch test series. Twenty-five of 1502 eczema patients showed reactions (1.7%), but none had any relevant history. At serial dilution test only one patient reacted to 1.0% cadmium; all the other dilutions applied gave negative reactions. Analysis by atomic absorption spectrophotometry of the cadmium chloride used for patch testing showed that it contained less than 1 microgram/g of chromium, copper, cobalt and nickel. The conclusion is that no certain case of contact allergy to cadmium chloride has been revealed. An experimental study using the guinea pig maximization test is in progress.