Wells' syndrome possibly caused by hematologic malignancy, influenza vaccination or ibrutinib: A case report.

Background: Wells' syndrome (eosinophilic cellulitis) is an uncommon eosinophilic dermatosis of uncertain pathogenesis, characterized by clinical polymorphism and suggestive but nonspecific histopathologic traits. Its course is recurrent, and response to therapy is unpredictable. In a case in which the patient has a number of potential triggers for the manifestation of Wells' syndrome skin rash, the treating physician must decide or must make an assumption in order to establish the most likely clinical scenario.