Infectious complications in polymyositis and dermatomyositis: a series of 279 patients

To assess the prevalence and characteristics of severe pyogenic, nonpyogenic, and opportunistic infections in polymyositis and dermatomyositis (PM/DM) patients and to evaluate the predictive values for infections on clinical presentation and biochemical findings of PM/DM to detect patients at risk for such infections.

The medical records of 279 consecutive PM/DM patients in 3 medical centers were reviewed.

One hundred four severe infections occurred in our patients (37.3%), ie, pyogenic (n = 71) and nonpyogenic/opportunistic infections (n = 33). Pyogenic infections were mainly due to aspiration pneumonia (n = 46) and calcinosis cutis infection. Thirty-three PM/DM patients developed nonpyogenic/opportunistic infections that were due to the following: Candida albicans, Pneumocystis jiroveci, Aspergillus fumigatus, Geotrichum capitatum, Mycobacterium (avium-intracellulare complex, xenopi, marinum, peregrinum, tuberculosis), Helicobacter heilmanii, cytomegalovirus, herpes simplex and zoster virus, hepatitis B and C, JC virus, Leishmania major, Strongyloides stercoralis. Esophageal dysfunction, ventilatory insufficiency, malignancy, and lymphopenia were significantly more frequent in the group of PM/DM patients with infections.

Our study underscores the high frequency of infections in PM/DM, resulting in an increased mortality rate. Our results suggest that prophylaxis against pyogenic infections should be routinely recommended for patients with PM/DM, including regular physical examination of lungs to depict aspiration pneumonia as well as risk factors of aspiration pneumonia. Finally, because a great variety of micro-organisms may be responsible for opportunistic infections, it seems difficult to initiate primary prophylaxis in PM/DM patients exhibiting risk factors for opportunistic infections.