[Cutaneous granulomatous lesions disclosing ataxia-telangiectasia].

INTRODUCTION: Idiopathic cutaneous granulomatous lesions are exceptionally described in the course of congenital immunodeficiency, including ataxia-telangiectasia. CASE REPORT: We describe a new case of a 28-month girl who presented granulomatous skin lesions revealing a previously unknown ataxia-telangiectasia in the absence of typical neurologic signs, telangiectasia and infectious complications. The clinical aspect showed infiltrated erythemato-squamous plaques and nodules predominating on the face and limbs. These lesions increased in number without remission. Histological examination revealed a nodular, lymphohistiocytic infiltration with granulomatous tendency in the deep dermis and the hypodermis. Before the onset of skin treatment, the child developed an Epstein-Barr-virus related lymphoproliferation. Immunoglobulins and oral corticosteroids associated with chemotherapy permitted the regression of the granulomatous lesions but not of the fatal spread of the lymphoproliferative syndrome. DISCUSSION: These rare cutaneous manifestations are important to know because they can be the initial sign of an immunodeficiency. Clinical and histological aspects are characteristic. They are eventually associated with visceral granulomatous lesions. Physiopathology remains hypothetical. An abnormal immune response to an undetermined antigenic stimulation could be suspected in this particular context. The question of a correlation between these lesions and a proliferative syndrome remains open.