Breaking the Blister: A Case Report of Bullous Wells’ Syndrome Resolved with Oral Terbinafine

Eosinophilic cellulitis (Wells' syndrome) is a rare inflammatory dermatosis, characterized by erythematous skin lesions, edema, and eosinophilic infiltration into the dermis. While typically affecting the limbs, it is uncommon for the condition to present as bullae on the feet. Most cases are idiopathic; however, triggering factors may include arthropod bites, certain medications, and viral, bacterial, or parasitic infections. In this case, a 52-year-old woman presented with recurrent pruritic, blistering eruptions on her feet over the past year. The lesions were non-responsive to multiple treatments, including topical and oral steroids, several antibiotics, and methotrexate. She was diagnosed with eosinophilic cellulitis by histopathology, possibly triggered by tinea pedis and onychomycosis. A three-month course of oral terbinafine resolved her fungal infection and recurrent eosinophilic cellulitis. This atypical presentation, including persistent scaly patches and bullae resistant to known treatments for eosinophilic cellulitis, highlights the challenges clinicians face when diagnosing this condition among a broad differential. It should be considered for any unexplained recurrent cellulitis-appearing inflammatory skin condition, not responsive to usual therapy. Additional triggers of eosinophilic cellulitis should be considered beyond those already identified in the literature, such as tinea pedis and onychomycosis as presented in this unique case. Addressing the underlying cause may lead to complete remission of eosinophilic cellulitis.