Clinical, immunohistochemical, and electron-microscopic findings in gold dermatitis

The clinical, immunohistochemical, and electronmicroscopic features of 13 consecutive patients with gold dermatitis were analyzed: 12 developed an eczematous dermatitis and one a lichenoid dermatosis. The patients had received intramuscular sodium aurothiomalate therapy from 1 month to 4 years before the dermatitis broke out. After cessation of gold therapy, the dermatitis persisted for 1-11 months. A relatively sparse perivascular mononuclear cell infiltrate was found in the affected skin in all cases. With immunoperoxidase staining, most of the infiltrating cells were shown to be OKT-4-positive T-helper lymphocytes. A majority of the infiltrating cells were Ia, i.e., HLA class II antigen, positive. Clearly increased numbers of dermal OKT-6-positive Langerhans' cells were also seen. In epidermis, on the contrary, the expression of both OKT-6 and Ia markers on dendritic cells was decreased. However, electron-microscopic examination revealed large numbers of macrophage-like cells and the Langerhans cells were activated, often in apposition to mononuclear cells within the epidermis. No correlation was observed between the immunohistological findings and the amount of gold received, the duration of gold therapy, and the interval between the last gold injection and biopsy, respectively, although peripheral blood eosinophilia was more common during 5-10 months of gold therapy. There were no specific findings in the patients in whom dermatitis lasted several months after discontinuation of the therapy. Our findings support the view that immunological mechanisms operate in the development of gold dermatitis, although the exact mechanisms remain unknown.