2025 – PAGE 162 – DERMATOLOGY

ERYTHEMA MULTIFORME

See the Stevens-Johnson syndrome section for more information on erythema multiforme. Look for target lesions.

THE NEWBORN RASHES

MILIARIA RUBRA

Look for very superficial vesicles that are easily ruptured in a case of miliaria rubra. This occurs due to obstruction of sweat glands and is also called “prickly heat rash.”

IMAGE: www.pbrlinks.com/MILIARIA1

MNEMONIC:  Miliaria sounds like malaria, which is usually found in hot countries where you sweat!

MILIA

Milia are small, pearly inclusion cysts that look like little white heads. There’s NO associated erythema. If milia are on the nose, they can be very easy to confuse with SEBACEOUS HYPERPLASIA.

IMAGE: www.pbrlinks.com/MILIA1
IMAGE: www.pbrlinks.com/MILIA2

SEBACEOUS HYPERPLASIA

In sebaceous hyperplasia, pinpoint white-yellow papules appear on the nose and central face. There is NO associated erythema. It results due to maternal androgen exposure and is benign.

IMAGE: www.pbrlinks.com/SEBACEOUSHYPERPLASIA1
IMAGE: www.pbrlinks.com/SEBACEOUSHYPERPLASIA2

ERYTHEMA TOXICUM NEONATORUM

Erythema toxicum neonatorum is seen in up to 50% of newborns and consists of erythematous macules with raised central lesions (papules or vesicles). This is usually seen at birth or by DOL 2. It is a benign rash with an unknown etiology. It usually disappears by DOL 7. Diagnose by noting eosinophils on microscopy.

IMAGE: www.pbrlinks.com/ERYTHEMA-T1

MNEMONIC: Although the name “TOXICum” suggests otherwise, this is a NON-toxic rash resulting in non-toxic looking babies.

MNEMONIC: This is an Early, Erythematous, “Eosinophilled” rash called Erythema toxEEEcum.

TRANSIENT NEONATAL PUSTULAR MELANOSIS

Transient neonatal pustular melanosis is more common in African-American kids. This is a benign rash with NO associated erythema. It starts in utero and is PRESENT AT BIRTH. It resolves within a few days but can leave hyperpigmented macules for a while. Diagnose by examining contents and looking for PMNs on Tzanck smear.

IMAGE: www.pbrlinks.com/TRANSIENT1
IMAGE: www.pbrlinks.com/TRANSIENT2  

MNEMONICS:  Transient neonatal PUStular melanosis should remind you of the PMNs on the Tzanck smear in the PUS-like contents of these PUStules. MELANosis should make you think about dark-skinned individuals (AA kids) and the dark macules that can be left behind.