Immaturity of organs often contribute to skin conditions that are not normally seen in older children and adults. While some rashes indicate the presence of underlying disease, most are benign and do not require treatment.

Some rashes result from normal newborn vascular physiology (blood vessels responding inappropriately to environmental stimuli).

Known causes of rashes include irritation and infection (bacterial, fungal or viral). Rashes that require treatment can be helped by use of gentle cleansers, moisturizers, antiseptic creams, and anti allergic drugs.

Skin Changes Due to Vascular Physiology

Cutis marmorata: Involves the trunk, arms and legs symmetrically. This is as a response to cold that generally resolves when skin is re-warmed. Some children may retain this condition for the first few years of life.

Harlequin color change: Infants who have been placed on their sides can develop this harmless condition. Usually appears in the first week of life and may last for 3-4 weeks. The lower side of the body is red while the upward side is relatively pale. This color change may develop suddenly and persists for half an hour or so and usually resolves with increased movement or crying. As the brain grows and matures, the condition disappears.

Other Harmless Rashes of Infants

Erythema toxicum neonatorum: Reddish spots and pimples on the face, trunk, and proximal extremities that develop into pustules (whiteheads).  Can be seen at birth, but more often during the first week of life .  About   70% of infants are affected and resolves in a few weeks

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Transient neonatal pustular melanosis: Raised blisters and pustules that rupture easily, leaving a small, pigmented spot. May affect entire body, including palms and soles. Occurs in up to 5% of black infants, and less than 1% of white newborns. Usually fades over a month or so.

Acne neonatorum: Resembles adolescent acne. Usually seen on the forehead, nose and cheeks. Rarely over the chest. Nearly  20% of newborns develop this condition and resolves within a month or two without leaving any scars.

Milia: These rashes are characterized by white or yellow pimples, 1-2 mm in size. Seen on the face, upper trunk, extremities, penis or mucous membranes. Occurs in 50% of infants and disappears within 2-3 months.

Miliaria: Consists of 2 common and distinct forms.

• Miliaria crystallina with small blisters on the head, neck, or trunk. Each blister resolves within hours to days.
• Miliaria rubra (heat rash) with small, reddened pimples and blisters. Can be prevented by avoiding overheating.

Seborrheic dermatitis (Cradle Cap): Most commonly seen. Consists of red and oily scales on the head, face, neck and ears. Usually resolves within several months. Scales can be removed with a soft brush after shampooing hair. Vegetable oil can be used to soften the scales prior to washing. Severe cases can be addressed with tar-containing shampoos, antifungals or mild topical steroids.