Approach to a rash in the well newborn and infant: Clinical sciences

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Introduction0:00–0:27

Rashes in well appearing newborns and infants are usually benign and self limited. These rashes can be associated with factors like hormonal shifts, immature circulation and environmental exposures, but occasionally rashes have no apparent cause.
Newborn and infant rashes can be categorized by age of onset and by rash appearance and distribution. Now, if a well appearing newborn or infant presents with a rash, first, you should obtain a focused history and physical exam and assess your patients age at the onset of the rash.

History & physical examination0:27–0:38

Let's start with rashes that appear before one week of age. In this case, your next step is to assess the rashes appearance.

< 1 week0:38–0:47

First, let's take a look at newborns with skin peeling. In this case, you should consider physiologic desquamation.

Physiologic desquamation0:47–1:24

While most newborns experience mild skin peeling more extensive skin peeling is seen in post term neonates. Physical exam reveals desquamation primarily on the hands and feet and it may extend to the limbs or trunk, especially if your patient is post term with these findings.
You can diagnose physiologic desquamation. This benign and self limited skin condition represents the natural shedding of the outer skin layer and requires no treatment.
All right, let's move on to rashes that present with transient color changes. In this case, you should assess the rashes pattern of distribution.

Transient color changes 1:24–1:34

First, if the color change is unilateral, you should consider a Harlequin color change. Caregivers may report a sudden onset of redness occurring exclusively on one side of the body which resolves within 20 minutes during the physical examination place the infant on their side and you may observe unilateral erythema of the dependent side with a clear demarcation along the midline.

Harlequin color change1:34–2:34

Based on these findings, you can diagnose harlequin color change. Although the color change appears dramatic.
This phenomenon is benign, self limited and does not require intervention heres a clinical pearl to keep in mind. Some infants are born with a reddish pink flat patch on the back of their head or neck that blanches with gentle pressure.
This is a common vascular birthmark called a nevus simplex or more commonly a salmon patch or stork bite that typically fades over the 1st 18 months of life.
Now, let's move on to color changes involving the distal extremities. In this case, you should consider acrocyanosis, especially if your patient is under two days old.

Acrocyanosis2:34–3:14

Newborns typically present with bluish discoloration of the hands and feet on the physical examination. You may notice that the extremities feel slightly cool to the touch and cyanosis is present in the hands and feet while the trunk remains well perfused and warm.
With these findings, you can diagnose acrocyanosis. This is a benign and transient phenomenon related to vasomotor immaturity which resolves when the infant is warmed.
Lets finish by discussing infants with widespread color changes of the skin. In this case, you should consider cutis marmorata.

Cutis marmorata3:14–4:11

These infants typically develop symmetric modeling of the skin often after cold exposure that resolves when the infant is warmed.
During the physical examination, you will see a distinctive lacy reticulated purple or pink coloration often on the trunk arms and legs.
If you see this diagnose cutis marmorata, which is a common phenomenon that can appear at any time during the first few months of life.
Here's another clinical pearl. Some infants are born with bluish gray spots on the back extremities or buttocks that don't change with temperature.
This benign finding is called congenital dermal melanocytosis, which is a common birthmark that is often mistaken for nonaccidental trauma since it appears similar to a bruise.
Now, let's go back and take a look at infants with rashes that consist of papules or pustules. In this case.

Papules/pustules4:11–4:22

Your next step is to assess the rash distribution. If the rash is widespread, consider transient neonatal pustular melanosis or erythema toxicum neonatorum.

TNPM4:22–5:04

First, let's discuss transient neonatal pustular melanosis. These infants typically have a rash that is present at birth with the exam revealing Vesico pustular lesions on a nonerythematous base.
Most often, the acral skin surfaces are spared after the rash resolves. The skin is left with hyperpigmented macules surrounded by colette of scale these findings are highly suggestive of transient neonatal pustular melanosis.
This rash is a benign condition that resolves spontaneously within a few weeks. On the other hand, erythema toxicum neonatorum usually begins 2 to 3 days after birth and can persist during the first week of life.

ETN5:04–6:04

Physical exam reveals macules or papules surrounded by a blotchy erythematous base resembling fleabites. Most often, the acral skin surfaces are spared.
These findings are highly suggestive of erythema toxicum neonatorum, which is a benign condition that resolves on its own within about 10 days.
Here's a high yield fact, transient neonatal pustular melanosis and erythema toxicum neonatorum are clinical diagnoses. However, if the diagnosis is unclear, consider performing a cytologic examination of fluid from a pustular lesion in transient neonatal pustular melanosis cytologic examination will reveal a predominance of neutrophils.
While in erythema toxicum neonatorum, it will reveal numerous eosinophils. Next, let's discuss papular or pustular rashes that are localized.

Sebaceous gland hyperplasia6:04–6:41

In this case, you should consider sebaceous gland hyperplasia or milia. Let's start with sebaceous gland hyperplasia, which is associated with tiny yellow bumps on the face.
The physical exam will reveal yellow papules between one and two millimeters in size most commonly on the nose and sometimes on the cheeks.
With this finding you can diagnose sebaceous gland hyperplasia, which is a benign and transient condition caused by androgenic stimulation of sebaceous glands on the flip side, newborns with milia present with tiny yellow bumps on the skin that develop within the first month of life on physical examination, you will likely see firm pearly yellow papules between 1 to 3 millimeters in size, mostly on the face, nose, chin or forehead.

Milia6:41–7:09

If so, you can diagnose milia. These lesions are benign keratin containing cysts that resolve spontaneously over several months.
All right. Now, let's go back and discuss patients who are one week or older in this case.

> 1 week7:09–7:18

Again, you should first assess the rash appearance if the rash is vesicular, consider miliaria. In this case, history reveals a widespread rash that might have started after exposure to a warm environment.

Miliaria7:18–8:08

Exam, findings include tiny scattered vesicles which could be associated with erythema if this is the case diagnose miliaria.
Now, here's a clinical pearl to keep in mind, all subtypes of miliaria are benign transient and result from sweat gland obstruction.
One example is miliaria crystallina, which typically presents with tiny non erythematous vesicles that rupture easily and disappear within a day.
Another one is miliaria rubra, also called heat rash, which can present at any age with widespread vesicles and erythema often following heat exposure.
Now, let's discuss rashes that consist of plaques or macules in these patients. Your next step is to assess the rash distribution.

Plaques/macules8:08–8:17

If the rash involves the diaper area, consider diaper dermatitis. These babies typically have a history of prolonged skin contact with a wet diaper causing irritation of the diaper exposed skin.

Diaper dermatitis8:17–9:19

The physical exam usually reveals bright red erosions on the convex skin surfaces. If left untreated, a secondary infection with candida may occur.
In this case, you could detect involvement of the perineal folds as well as satellite lesions which are small red patches surrounding the primary rash.
With these findings, you can diagnose diaper dermatitis. Now, here's a clinical pearl, prolonged contact with irritants such as urine and stool can cause a breakdown of the skin's natural barrier.
Resulting in dermatitis management involves diaper hygiene which includes frequent diaper changes and gentle cleansing along with protective barrier creams.
Management of candida dermatitis includes topical antifungals and diaper hygiene. Lets move on and discuss rashes that involve the scalp and skin folds.

Seborrheic dermatitis9:19–10:23

In this case, you should consider seborrheic dermatitis, which is also known as cradle cap affected infants have a greasy flaky rash involving the scalp, face ears or neck.
Physical examination typically reveals yellow scaly patches with an erythematous base. Occasionally with associated cracking or weeping.
The rash will be noted on areas where there are numerous sebaceous glands such as the scalp behind the ears, eyebrows or in skin folds.
With these findings, you can diagnose seborrheic dermatitis, which is a common and benign skin condition caused by sebum overproduction.
Here's a clinical pearl seborrheic dermatitis generally does not cause discomfort but it can be managed with gentle cleansers or emollients or in some cases, a mild topical steroid or antifungal cream.
In most instances, it resolves over time as the infant's skin matures next up are rashes that appear on the cheeks and flexural skin surfaces.

Atopic dermatitis10:23–11:28

In this case, consider atopic dermatitis. There is often a positive family history of atopy and infants classically present with a pruritic rash with frequent flare ups.
Physical examination typically reveals dry erythematous scaly patches with lichenification on the cheeks or flexural surfaces of the skin such as the antecubital fossa.
With these findings, you can diagnose atopic dermatitis. Here's a high yield fact to keep in mind in Children, an eczematous rash typically involves flexural skin creases or the cheeks.
Whereas in adults, eczema more commonly involves the extensor surfaces of the knees and elbows. In both groups, patients can develop coin shaped lesions known as nummular eczema, which is commonly confused with ringworm.
Management of eczema includes emollients to restore the skin barrier and topical corticosteroids to reduce inflammation and pruritus.
Finally, let's take a look at the rash associated with papules and pustules. In this case, consider neonatal acne.

Neonatal acne 11:28–12:04

These infants usually develop small red bumps at around three weeks of age. The physical exam will reveal an assortment of inflamed papules and pustules with an absence of comones usually limited to the face.
With these findings, you can diagnose neonatal acne. Unlike adolescent or adult acne, neonatal acne is self limited and resolves without treatment once hormone levels stabilize.
All right, as a quick recap rashes in well appearing newborns and infants are usually benign and self limited. These rashes can be associated with factors like hormonal shifts, immature circulation and environmental exposures.

Review12:04–12:28

But occasionally rashes have no apparent cause. Newborn and infant rashes can be categorized by age of onset and by rash appearance and distribution.