A 17-day old female presents with a rash that started one week ago. The rash initially started on her back and then spread to her arms and chest. She was seen by her PCP and was given mupirocin, which has somewhat helped the rash. Two days ago, she developed an increasingly large “bump” on the back of her head.

ROS negative for fever, congestion, vomiting, diarrhea, sick contacts. Infant has otherwise been feeding well and had normal urine output

Pregnancy course uncomplicated, negative STI, HSV, GBS screening. Uncomplicated vaginal delivery at 40 weeks, no forceps or vacuum assistance required. Umbilical cord fell out on DOL 8, denies discharge from stump.

Temp: 36.5 HR 136 RR 44 BP 94/51 100% on RA

General:  Alert.  well-appearing infant.  
Skin:  2 x2 cm area of erythema and fluctuance on her occipital scalp, no drainage.  There are pustules and erosions scattered on abdomen and torso. The base of the pustules are non-erythematous. The pustules are filled with pus, one intact pustule near left nipple. Multiple erosions on left upper extremity. There are no vesicles, no bullae.
Head:  Anterior fontanelle soft and flat.   frenulum intact,  no step-offs or deformities.
Neck:  Supple
Eye:  Pupils are equal, round and reactive to light
Ears, nose, mouth and throat:  Oral mucosa moist.  no lesions or ulcers in mucus membrane .  
Cardiovascular:  Regular rate and rhythm
Respiratory:  Lungs are clear to auscultation
Gastrointestinal:  Soft.  Non distended. 

Ultrasound shows a 2.7 cm subcutaneous abscess. CBC shows WBC of 19, pro cal of 0.16 and elevated eosinophils. Infant continues to look well appearing, is breast feeding and remains afebrile in the ED.

The LP is obtained, and patient is started on empiric antibiotics and acyclovir.