Infections au cours des polymyosites et des dermatomyosites

Infections result in increased mortality rates in patients with polymyositis/dermatomyositis, leading to death in 9 to 30% of cases. The following parameters can be considered of predictive value for infection onset in polymyositis/dermatomyositis: age, lymphopenia, esophageal dysfunction, ventilatory insufficiency, interstitial lung disease, calcinosis cutis, as well as higher mean daily doses of steroids. A great variety of microorganisms may be responsible for pyogenic and opportunistic infections in polymyositis/dermatomyositis. Opportunistic infections are more often due to mycobacteria and fungi (Pneumocystis jiroveci, Candidasp.). Because a great variety of microorganisms may be responsible for opportunistic infections, it seems difficult to initiate primary prophylaxis in patients with polymyositis/dermatomyositis who exhibit risk factors for opportunistic infections. Primary prophylaxis of Pneumocystis jirovecipneumonia should be given in the group of patients exhibiting CD4-cell count lower than 250/mm(3). Vaccination should be performed in patients with polymyositis/dermatomyositis, prior to immunosuppressive therapy institution.