Neonatal dermatology

Benign conditions

Neonates have rashes of all shapes and sizes. It’s important for us to be able to reassure parents where appropriate.

In all the following skin conditions, the baby is systemically well. If the baby is not well, the rash is just an incidental finding or your diagnosis is incorrect.

Erythema toxicum

• There are usually central papules or pustules surrounded by areas of erythema
• Absence of mucosal, palmar and plantar involvement
• Benign, self-limiting, asymptomatic disorder of unknown aetiology
• Occurs in up to 50% of term infants; 5% preterm infants
• Presents at 24-48 hours of life, fades within 5-14 days, but recurrences may occur for several weeks
• Smear (Tzanck smear) of pustule reveals eosinophils

Transient neonatal pustular melanosis

• Self-limiting dermatosis of unknown etiology
• Occurs more frequently in black males
• Usually presents at birth
• Pustule on non-erythematous base, crusts over several days, which ruptures and leaves a hyperpigmented macule with a collarette of fine scale
• Hyperpigmentation fades in 3 weeks to 3 months
• Smear of pustule reveals neutrophils

Congenital dermal melanocytosis

• Flat, slate-grey to bluish-black, poorly circumscribed macules/patches
• Most commonly located over the lumbosacral area and buttocks
• Common in black, Asian, and Hispanic infants
• Usually fades by 7 years of age

Cutis marmorata

• Transient, net-like (reticular), reddish-blue mottling
• Caused by variable vascular constriction and dilation
• Response to chilling resolves with warming
• Benign in neonates and usually subsides by 6 months, but may persist longer in very fair-skinned individuals
• If persists past 6 months, maybe a marker for hypothyroidism

Congenital nevomelanocytic nevi

• Pigmented macules or plaques with dense hair growth
• Giant CNN (>2% of TBS) are associated with a 2-10% lifetime risk of melanoma
• Highest risk of malignant change occurs in the first 3-15 years of life
• Early treatment with full-thickness excision followed by grafting if possible, otherwise close observation
• Small to medium-sized CNNs are also associated with a higher risk of malignant change than acquired moles, but the incidence is unknown

Acrocyanosis

• Hands and feet become variably and symmetrically blue
• Resolves with the warming of the skin
• Recurrence is unusual after one month of age

Haemangioma

• Congenital vascular malformation
• Occur in 10% of all newborns
• Presents in the first few months of life
• Caused by dilated capillaries occupying the dermal and subdermal layers with endothelial proliferation.
• Rapid growth for the first 6-12 months, then a plateau period, then slow involution
• 50% involute by age 5, 90% by age 9

—Refer to dermatology if the lesion involves a vital structure or if there are multiple lesions

Salmon patch/stork bite

• Vascular malformation;
• Seen in 60% of infants
• “Stork bite” macular pink areas of distended capillaries found on the nape of the neck, upper eyelids, nose, or upper lip.
• They have diffuse borders, blanch with pressure, and become pinker with crying.
• Fades in the first year of life

Port wine stain

• Purplish-red vascular malformation present at birth
• Lesions do not enlarge but remain flat and persist
• When port wine stain involves the ophthalmic branch of the fifth cranial (trigeminal) nerve, it can be associated with Sturge-Weber syndrome
• Sturge-Weber syndrome involves seizures, mental retardation, hemiplegia, and glaucoma

Neonatal acne

• Develops in up to 20% of newborns (forehead and cheeks)
• Maternal and endogenous androgen; possible involvement of Malassezia species (controversial) thought to play a role in the pathogenesis, but exact aetiology unknown
• Lesions involute within 1-3 months, treatment usually unnecessary – does not scar

Milia

• Pearly yellow papules usually on the face (1-2 days after delivery)
• Small, white pearly globules. May be 1-2mm in size
• Usually present on the cheeks, chin, forehead or scalp
• Larger single milia may occur in the region of the foreskin, scrotum or labia majora
• Occur in 50% of newborns
• Common, benign, keratin-filled cysts
• Usually resolve in the 1st month of life

Epstein pearls

• The oral counterpart of facial milia. Can be seen on the midline of the palate or on the alveolar ridges
• This occurs in approx 60% of neonates
• No treatment needed

Miliaria

• Results from obstruction to the flow of sweat and rupture of the eccrine sweat gland
• Miliaria crystallina – superficial 1-2mm vesicles on non-inflamed skin- stratum corneum
• Miliaria rubra (heat rash) – small red papules and pustules. Pruritic-intra epidermal
• Occur in response to thermal stress
• Usually erupt in crops in the intertriginous areas, scalp, face, and trunk

Concerning conditions

Epidermolysis bullosa

• Group of inherited mechano-bullous disorders
• Blisters form after mild friction or trauma
• Three types: epidermolytic EB, junctional EB, dermolytic EB
• Skin biopsy distinguishes types and determines prognosis
• Prenatal diagnosis is now possible for a number of variants for which gene markers are available
• Treatment is symptomatic and supportive

Congenital syphilis

• Mucocutaneous lesions usually appear between 2-6 weeks of age
• The most common finding is a papulosquamous eruption beginning in the palms and soles and spreading over extremities, face and trunk (pemphigus syphiliticus)
• Diagnosis confirmed with serological studies of the serum and CSF
• Early diagnosis and treatment with high-dose penicillin prevent late complications
• Newborns with the disease can also be born premature, have poor growth, and develop hepatosplenomegaly and rhinorrhea

Congenital rubella

• Blueberry muffin lesions
• Seen in severe disseminated disease with jaundice, pneumonitis, meningitis, bony abnormalities, thrombocytopenia
• Congenital rubella is associated with cataracts, microphthalmia, glaucoma, congenital heart disease
• Blueberry muffin lesions can also be seen in congenital CMV and toxoplasmosis
• Can confirm the diagnosis with serologic testing

Herpes simplex

• Of infected babies, 70% develop the skin rash and 90% of these children go on to develop systemic disease
• Clustered red papules and vesicles, then become pustular, denuded, crusted, and hemorrhagic over the following 2-3 days
• Diagnose by PCR of the lesion
• Treat with acyclovir as soon as the infection is suspected to prevent disseminated disease and morbidity/mortality

Neonatal varicella

• Early exposure in utero during 1st trimester can rarely lead to neonatal varicella syndrome: linear scars, limb anomalies, ocular defects, and CNS involvement
• Late exposure in 3rd trimester increases the risk of the baby acquiring the disease during the neonatal period (the closer to delivery, the higher the risk)
• Vesicles usually develop over the first 3-10 days of life
• Dissemination can lead to pneumonitis, encephalitis, purpura with haemorrhage, hypotension, and death
• If a newborn is at risk, should consider varicella-zoster immune globulin or IVIG
• Start acyclovir early if lesions are suspicious for varicella
• Confirm diagnosis with DFA or PCR of a lesion

Aplasia cutis congenita

• Often inherited as an AD trait
• Absence/failure of formation of a localized area of scalp or skin, usually a single lesion located over the vertex of the scalp
• Treatment is supportive until the lesion is healed
• Leaves an atrophic, hairless scar that can be excised later in life
• Less commonly, the trunk and extremities are involved and lesions may be associated with limb defects, epidermolysis bullosa, and chromosomal abnormalities

Neonatal lupus erythematosus

• Annular erythematous plaques with a central scale
• Transplacentally acquired ssA (Ro) and ssB (La) Ab is thought to play role in the pathogenesis
• May be triggered or exacerbated by sun exposure
• Associated with heart block, hepatosplenomegaly, anaemia, leukopenia, thrombocytopenia, and/or lymphadenopathy
• Except for cardiac involvement, usually resolves in 6-12 months
• May need topical steroids, rarely requires systemic steroids

Incontinentia pigmenti

• Neurocutaneous syndrome
• X-linked dominant (IKBKG gene), lethal in males
• Starts out with patches of erythema and blisters that follow the lines of Blaschko -> warty plaques by several weeks to months -> increasing pigmentation at 2-6 months that look like marble cake swirls -> fade to hypopigmented patches in late childhood
• Associated defects in the CNS, eye, dentition, heart, and skeletal system