Dyshidrotic Eczema Pompholyx Palms

A 26-year-old female accountant with a history of atopic dermatitis and seasonal allergic rhinitis presents with a three-week history of severely pruritic blisters on both palms and lateral fingers. She reports the outbreak began during a stressful audit period and worsened after prolonged handwashing with detergent. She wears nickel-containing costume jewellery daily. On examination, the structure marked **A** shows deep-seated, clear, fluid-filled vesicles resembling tapioca pudding arranged in crops along the lateral aspects of the fingers with no surrounding erythema. Bacterial swab and KOH preparation are negative. Which of the following is the most likely diagnosis?