Relapsing Legionella pneumophila cellulitis: a case report and review of the literature.

Legionella spp. rarely cause soft tissue infections, with only a few cases reported and usually in the setting of immunocompromise. We report a case of L. pneumophila cellulitis, without pneumonia, in a 65-year-old immunocompromised woman. The patient had a history of interstitial lung disease and idiopathic thrombocytopenic purpura, for which she was receiving high-dose corticosteroids, and had recently experienced an episode of L. pneumophila cellulitis of the lower extremity, which responded to an extended course of levofloxacin. She was initially transferred to this institution for definitive workup of presumed B cell lymphoma and, during her hospital course, suffered a relapse of L. pneumophila-associated cellulitis that responded promptly to azithromycin. More unusual organisms such as Legionella spp. should be considered in the etiology of cellulitis, particularly in the setting of immunocompromise, in cases that are refractory to conventional antibiotics routinely administered for skin and soft tissue infections.