Generalized granuloma annulare and giant cell arteritis.

Granuloma annulare (Gan) and giant cell arteritis (GCA) share common histologic features. In Gan, a disease characterized by the presence of palisading granulomas usually in the dermis, the main alteration is the presence of elastic fiber degeneration and it strongly suggests that the primary target leading to the development of this disorder is the injury to the elastic tissue. On the other hand, in giant cell arteritis (GCA), a vasculitis involving large-and middle-sized blood vessels, the main histologic features are the disruption of the internal elastic lamina and the nonsuppurative granulomatous giant cell infiltrate, which seems to be focused around the disintegrated elastic fibers. Due to this, these two conditions appear to be related. However, to the best of our knowledge, only one case of association of generalized Gan and GCA is described in the literature. We herein report a new case of generalized Gan in a patient previously diagnosed with biopsy-proven GCA. Both diseases were successfully treated by oral prednisone. Although the etiology of generalized Gan and GCA remains still unknown, they seem to be immunologically mediated conditions showing predominance of T-cells in the inflammatory infiltrate.