Routine patch testing with cadmium chloride

Area of Science:

• Dermatology
• Toxicology
• Allergy Research

Background:

• Cadmium chloride is used in patch testing for eczema patients.
• Understanding potential allergens like cadmium is crucial for accurate diagnosis and treatment.

Purpose of the Study:

• To evaluate the prevalence and significance of contact allergy to cadmium chloride in eczema patients.
• To determine if routine patch testing with cadmium chloride elicits allergic reactions.

Main Methods:

• A 2.0% cadmium chloride solution in distilled water was applied as part of routine patch testing for 1502 eczema patients over 22 months.
• Positive reactions were further assessed using serial dilution tests.
• The purity of the cadmium chloride solution was analyzed using atomic absorption spectrophotometry.

Main Results:

• 1.7% (25 out of 1502) of eczema patients showed reactions to cadmium chloride patch tests.
• Only one patient reacted to a 1.0% dilution, with other dilutions yielding negative results.
• Analysis confirmed the absence of significant chromium, copper, cobalt, and nickel contamination in the tested cadmium chloride.

Conclusions:

• No definitive cases of contact allergy to cadmium chloride were identified in this patient cohort.
• The low reaction rate and lack of relevant history suggest cadmium chloride may not be a common contact allergen.
• Further research, including animal studies, is ongoing to fully elucidate cadmium's allergenic potential.