What can cause a rash without redness on the forehead of a healthy newborn?

Bumpy Rash Without Redness on Newborn Forehead

The most likely diagnosis is milia, which presents as small white or flesh-colored papules without surrounding erythema, commonly appearing on the forehead, nose, and cheeks of newborns at birth. 1, 2

Primary Differential Diagnosis

Milia (Most Likely)

• Small white or yellow papules (1-2mm) without surrounding redness, present at birth 1, 2
• Result from retention of keratin within immature pilosebaceous units 1
• Most commonly located on forehead, nose, chin, and cheeks 1
• Require no treatment and resolve spontaneously within weeks to months 1, 2
• Can be differentiated from neonatal acne by their presence at birth and lack of inflammatory component 2

Closed Comedones (Neonatal Acne)

• Flesh-colored or skin-colored papules without erythema represent closed comedones 1
• Neonatal acne typically develops at 2-4 weeks of age (not at birth like milia) 1, 2
• When inflammatory component is absent, lesions appear as small bumps without redness 1
• Self-limited and resolves without treatment in most cases 2

Transient Neonatal Pustular Melanosis (Resolving Stage)

• After pustules rupture, leaves hyperpigmented macules with collarette of scale 1, 3
• In lighter-skinned infants, the hyperpigmentation may be subtle, appearing as slightly raised areas without obvious redness 3
• Present at birth or within first 24-48 hours 1, 3
• Benign and self-resolving, requires no treatment 1, 3

Critical Exclusions

When to Suspect Infection (Requires Immediate Evaluation)

• Any systemic signs including fever, poor feeding, lethargy, or irritability mandate immediate workup and parenteral antibiotics 4, 5
• Vesicular lesions (even without redness) in an ill-appearing infant could represent herpes simplex virus, which presents with vesicles in only 60% of cases 5
• Rapidly spreading lesions or pustules in premature infants require systemic antibiotics 4

Molluscum Contagiosum

• Flesh-colored or pearly white papules with central umbilication 6
• Uncommon in newborn period; typically appears after 6 months of age 6
• Highly contagious but usually resolves without intervention 6

Management Approach

For Well-Appearing Newborns with Non-Inflammatory Bumps

• Parental reassurance and observation is sufficient for milia and benign neonatal rashes 1
• Gentle cleansing with water or nonsoap cleanser 2-3 times weekly followed by bland emollient application 5
• Avoid attempting to express or remove milia, as this can cause scarring 1

Red Flags Requiring Further Evaluation

• Presence of systemic symptoms (fever >38°C, poor feeding, lethargy, irritability) 4, 5
• Rapidly spreading or changing lesions 4
• Pustules or vesicles in premature infants 4
• Associated petechiae (consider congenital cytomegalovirus) 2
• Copper-red maculopapular lesions on palms/soles (consider congenital syphilis) 2

Common Pitfalls to Avoid

• Do not use topical corticosteroids on infant facial skin due to increased systemic absorption risk, HPA axis suppression, and severe skin atrophy 7, 5
• Do not confuse milia (present at birth) with neonatal acne (develops at 2-4 weeks) 2
• Never delay antibiotics for imaging or workup in systemically ill neonates, even if the rash appears benign 4
• Recognize that absence of erythema does not exclude serious infection in an ill-appearing infant 5