An 8-year-old boy is brought in for evaluation of a collection of blisters on his finger, near the nail. The problem manifested about 6 days ago. The affected area is tender to touch. The child reportedly feels well, with no fever or malaise.
The patient has an extensive personal and family history of atopy. Since birth, he has had dry, sensitive skin and has experienced episodes of eczema, seasonal allergies, and asthma. Three months ago, he was admitted to the hospital with eczema herpeticum and successfully treated with IV acyclovir.
A cluster of vesicles is seen in the lateral perionychial area of the left third finger. Very modest erythema surrounds the vesicles, which contain cloudy yellow fluid suggestive of pus. There is a palpable lymph node in the left epitrochlear area.
The child is afebrile and in no distress. Patches of mild eczema are seen on the extremities and trunk.
What’s the diagnosis?