We present the clinical case of a five-year-old boy with atopic dermatitis since the first months of life, with no other personal or family history of interest. As an infectious history, he had suffered chickenpox a year earlier without complications and a lesion compatible with herpes labialis on his father a few days earlier.
The patient consulted the emergency department for vesicular, erythematous skin lesions that had been present for two days. Some of the lesions showed signs of impetiginisation without signs of cellulitis. The skin lesions were distributed on both lower and upper limbs and trunk. The rest of the examination was unremarkable. Fever of 38°C maximum since twelve hours before. No other symptoms. There was no family history of infection at the time of consultation.

On suspicion of Kaposi's varicelliform rash, it was decided to admit her for the start of intravenous treatment with acyclovir at 20 mg/kg/day. Oral amoxicillin-clavulanic acid 50 mg/kg/day and daily treatment with chlorhexidine were added to the treatment.
On admission, an analytical study was performed with a haemogram and biochemistry, without elevation of acute phase reactants, and serology was extracted for herpes simplex virus 1 and 2, Coxsackie, cytomegalovirus, toxoplasma, Epstein Barr virus, parvovirus and human herpes virus type 6.
The clinical course was favourable, with fever disappearing within 24 hours of admission and no systemic or cutaneous complications.
From the third day onwards, the lesions were all in the crusting phase with progressive detachment of the crusted lesions without incident.
Discharge was decided on the fourth day of admission, completing oral treatment with acyclovir for a further seven days.
One week after admission, the patient showed no signs of skin lesions except for his known atopic dermatitis. The serology result was negative for all the tests except IgM positive for herpes simplex virus type 1.