4th August 2020

A 3-year-old girl, Susie, with a history of atopic dermatitis is brought to A & E by her parents

A 3-year-old girl, Susie, with a history of atopic dermatitis is brought to A & E by her parents. They report a worsening eczema over the last 4-days, which is not responding to her usual eczema treatment. Susie has also developed widely distributed vesicle on her face, trunk, and forearms which she reports are painful and itchy. She appears lethargic and is feverish. How would you confirm the likely diagnosis? 

Select the SINGLE most appropriate investigation from the list below. Select ONE option only.