Bullous Wells' Syndrome: Case Report and Systematic Review

Background/Objectives: Wells' syndrome (WS) is an uncommon cutaneous disease with unknown etiology. Itchy bullous lesions and erythematous plaques characterize the bullous WS (BWS), a rare subtype of the syndrome. We describe the case of a woman affected by chronic lymphocytic leukemia who developed BWS and responded to the classic corticosteroid treatment. We also systematically reviewed the literature, analyzing the clinical, laboratory, and histological features and treatments of this rare disease. Methods: We used the databases Ovid MEDLINE, PubMed, and EMBASE with the following search terms: ((bullous Wells' syndrome [MeSH Terms]) OR (eosinophilic cellulitis)) OR (bullous eosinophilic dermatitis) to identify and compare case reports of BWS. Results: We analyzed 28 patients, including our case. They were primarily female adults with a median age of 44.92 years. Blood eosinophilia was common, and histologically, the tissue samples showed an eosinophilic-neutrophilic dermal infiltrate. From a clinical perspective, the bullae were typically associated with or preceded by other lesions, primarily urticarial plaques, and mainly involved the extremities. Possible triggering agents of BWS include medications, insect bites, malignancies, and autoimmune/infectious diseases. Systemic steroids constituted the first-line treatment. Recent studies described the efficacy of the anti-interleukin-5 monoclonal antibody Mepolizumab in refractory cases of WS. Conclusions: Diagnosis of BWS is often challenging due to the rarity of the disease, clinical polymorphism, and multiple differential diagnoses. Integrating clinical features with laboratory and histopathological findings is essential for achieving a definitive diagnosis. Although the causal link between WS and underlying neoplastic/autoimmune/infective conditions is not always present, this possibility should be taken into account and investigated for the best patient management.