Management of Neonatal Rashes in the Emergency Department (Infectious Disease CME)

Publication Date: December 2025 (Volume 22, Number 12)

CME Credits: 4 AMA PRA Category 1 Credits™, 4 ACEP Category I Credits, 4 AAP Prescribed Credits, 4 AOA Category 2-B Credits. CME expires 12/01/2028.

Specialty CME Credits: Included as part of the 4 credits, this CME activity is eligible for 2 Infectious Disease CME credits, subject to your state and institutional approval.

Authors

Chelsey Mitchell, MD

Fellow of Pediatrics in Emergency Medicine, New York-Presbyterian Morgan Stanley Children’s Hospital, New York, NY

Christine T. Lauren, MD, MHA

Associate Professor of Dermatology and Pediatrics, Columbia University Vagelos College of Physicians and Surgeons and New York-Presbyterian Hospital, New York, NY

Kelsey Fawcett, MB, BCh, BAO

Assistant Professor of Pediatrics in Emergency Medicine, New York-Presbyterian Morgan Stanley Children’s Hospital, New York, NY

Peer Reviewers

Sylvia E. Garcia, MD

Assistant Professor of Pediatric Emergency Medicine, Department of Emergency Medicine, Icahn School of Medicine at Mount Sinai, New York, NY

Victoria Gregg, MD

Assistant Professor of Pediatrics, Dell Medical School, The University of Texas at Austin, Austin, TX

Abstract

While most cases of neonatal rashes are benign and self-limited, certain neonatal skin conditions require prompt diagnosis and targeted treatment to prevent severe morbidity and mortality. Recognition of high-risk neonatal rashes and early intervention can significantly improve patient outcomes. Categorizing the rash can help delineate a differential diagnosis and determine whether the presentation and physical examination have features of a high-risk rash. This issue offers a strategic approach to the evaluation of neonatal skin conditions and offers guidance for differentiating benign findings from those that should raise concern and lead to further evaluation and management.

Case Presentations

CASE 1

A first-time mother brings in her 10-day-old boy because of a rash she noticed earlier in the day...

On arrival, the infant had a rectal temperature of 37.3°C and a heart rate of 156 beats/min. The nurse reports that he appears well overall. The mother tells you that she has no medical history, the baby was born full-term from a spontaneous vaginal delivery in a hospital setting, and that he was healthy at birth and discharged home shortly after. She tells you they have had many visitors, and she thinks that a cousin, who visited the infant right after delivery, might have had a facial rash.
A quick examination of the boy’s skin reveals a group of vesicles on his forehead.
What skin condition are you most worried it could be? For an afebrile, well-appearing neonate with a vesicular skin lesion, what diagnostic tests and treatment are necessary?

CASE 2

A 4-week-old girl is brought in by her mother for a worsening rash…

The mother tells you the girl is her third baby who was born vaginally after induction at 36 weeks due to maternal hypertension. The infant spent 1 week in the neonatal intensive care unit for respiratory distress before being discharged.
The mother says she is concerned because her newborn has had a rash that seems to be spreading. The rash started a week ago and was initially on the chest and now involves parts of the face, back, arms, and upper legs. It does not involve the diaper area. She says she is breastfeeding with some formula supplementation, which she started a couple of weeks ago.
On examination, the infant’s vital signs are within normal limits, and the baby appears very well but has ill-defined xerotic plaques, most notable on the extensor arms and legs, cheeks, and trunk.
What is the most probable cause of this rash? What advice would you provide this mother?

CASE 3

A 4-week-old boy was referred to the emergency department by his primary care doctor for evaluation of a rash…

The rash was noted this morning at the boy’s 1-month well-child check. The mother states the rash had been present for the last 1 to 2 days and has been rapidly spreading. The infant was born full-term without any complications and had been doing well until the skin changes were noted. No fevers were documented; however, the mother notes that he has been fussier and feeding less than usual.
On examination, the infant’s vital signs are remarkable for an elevated temperature to 37.9°C and a heart rate of 177 beats/min. He is crying, appears uncomfortable, and is difficult to console. Examination of the skin reveals diffuse erythema with accentuation in the neck and axillae. You also make note of some crusting around the eyes and mouth, and focal areas of desquamation on the neck, in addition to noticing a few new developing areas in the skin folds around the diaper area.
What diagnosis are you most concerned about? What are some options for treatment?

CASE 4

A 3-week-old girl with no significant medical history presents with a rash in her diaper area…

The mother states the area has become very red and raw and has been worsening over the past 7 days. The baby cries unconsolably whenever she urinates or has a bowel movement. The mother is applying nystatin cream, without any improvement.
On examination, the infant’s vital signs are within normal range. She is fussy but consolable. You notice a small infantile hemangioma on the chest, which the mother states has been there since 1 week of age and has gotten slightly more red. When examining the infant’s diaper area, you note diffuse erythema of the area extending over her labia majora and over her buttocks. In the center of her left buttock, you notice an annular ulceration about the size of a quarter, with a small amount of bleeding. The mother tells you she did not notice the bleeding beforehand.
What is the most likely diagnosis and how would you approach initial management?

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