RESUMO
A 35-year old woman presented with pustulosis palmaris et plantaris evolving in acute episodes parallel to those of a rheumatic disease consisting of bilateral sacro-iliac arthritis, manubriosternal fusion and sterno-clavicular arthritis. Her brother had spondylitis compatible with the diagnosis of pustular osteo-arthritis though without pustulosis. He presented with bilateral sacro-iliac arthritis, manubriosternal fusion, sterno-clavicular arthritis and an ossified fragment detached from the antero-inferior angle of C6. The two patients had the same HLA phenotype: A1, A9, B5, B41, CW4, DR2, DR4, absence of B27. In a specimen from the sacro-iliac joint the authors found active bone remodelling and inflammatory osteitis with fibrosis and infiltrates rich in mononucleate cells. An electron microscopic study--to the authors' knowledge, the first to be performed in such cases--demonstrated intracytoplasmic filamentous inclusions in two macrophages of the synovial fringe. Only one other case of the familial form has been published so far. Like the rheumatism of acne conglobata, the spondylitis of pustulosis palmaris et plantaris is one of the causes of sterno-costo-clavicular hyperostosis.