[Pyoderma gangrenosum and IgA gammopathy. Association with atrophic gastritis].

Pyoderma gangrenosum (PG) is a rare condition remarkable for its association with particular diseases, notably haemopathies and gastrointestinal diseases. As regards haemopathies, the associations most frequently encountered are with myeloid malignancies and monoclonal dysglobulinaemia. The association of PG with mainly inflammatory digestive tract diseases is also classical. The lack of publications concerning gastric atrophy and the dual haematological and gastric pathology which characterizes our case have prompted us to report it. A 60-year-old woman without significant history was admitted for PG on both knees, following vesiculo-bullous lesions. Laboratory examinations detected a normochromic anaemia tending to be macrocytic, a marked inflammatory syndrome and a monoclonal lambda light chain IgA peak at protein immunoelectrophoresis. Bone marrow biopsy, skeletal radiography and a search for Bence-Jones proteinuria were normal or negative. Colonoscopy showed no abnormality, but fibroscopy of the upper digestive tract revealed a severe gastric atrophy en plaques. Serum vitamin B12 level was moderately low, but there was no other sign of pernicious anaemia. After one month treatment with systemic corticosteroids, healing was obtained under replacement vitamin therapy. PG recurred a few months later; serum vitamin B12 level was normal, and the lesions healed after systemic corticosteroid treatment. In non-myelomatous dysglobulinaemia IgA is frequently found and there is no light chain predominance. PG often precedes dysglobulinaemia. Evolution towards a true myeloma seems to be exceptional. In a recent publication, 17 cases of association between PG and myeloma were mentioned, the IgA type being most common. Protein electrophoresis is indispensable in patients with PG. Five cases of congenital hypogammaglobulinaemia have been recorded, including three with IgA deficiency.(ABSTRACT TRUNCATED AT 250 WORDS)