CONTACT ALLERGY TO GOLD IN DENTAL PATIENTS

Gold sodium thiosulphate (GSTS) in patch test series commonly yields p ositive reactions. In this study of dental patients, the clinical rele vance of these positive reactions, the suitability of gold compounds a s patch test materials, and value of the lymphocyte proliferation test in gold contact allergy, were evaluated. The frequency of positive pa tch test reactions to GSTS was 12.4% in the dental series, Fifty-two p atients, only two of whom were male, were studied. Thirteen (25%) had had symptoms from jewellery or dental restorations. However, in most c ases gold allergy was subclinical. A 10% aqueous solution of gold sodi um thiomalate (GSTM) was almost as good as 0.5% GSTS in petrolatum as a marker of gold contact allergy, but 0.001% potassium dicyanoaurate ( PDCA) yielded a high percentage of false-negative results. Seventy-thr ee per cent of the subjects with positive patch tests to GSTS responde d to gold compounds in vitro in the lymphocyte proliferation test, whe reas 13 controls without gold contact sensitivity were negative. Consi stent results in skin and lymphocyte proliferation tests provide suppo rt for the concept that gold salt-induced 'allergic-like' reactions ar e truly allergic in nature.