Generalized perforating granuloma annulare associated with latent tuberculosis successfully treated with isoniazid:...

Generalized perforating granuloma annulare (GPGA) is a very rare form of granuloma annulare, with only 31 reported cases to the best of our knowledge. Furthermore, GPGA is a chronic disease that mimics many diseases, with no known exact etiology, resulting in a lack of specific clinical criteria leading to a lack of guidelines for diagnosis and therapy. In GPGA, papules are the predominant lesions followed by central crusting/scaling or umbilication; pustules, plaques, annular lesions or nodules are less frequent. We report a 66-year-old woman who presented with a 7-month history of mostly asymptomatic generalized infiltrated, flesh-colored to red-brown umbilicated or crusted papules. Histopathological findings were compatible with perforating granuloma annulare. Diagnostic workup revealed latent tuberculosis. To the best of our knowledge, this is the second published case of GPGA associated with latent tuberculosis and the first one that was successfully treated by isoniazid monotherapy. From our case we can speculate and support the theory that GPGA is a phenotypic granulomatous response to multiple etiologies and/or antigenic stimulation and that testing for tuberculosis should be seriously considered in the evaluation of patients with GPGA.