Newborn's rash linked to mother's antibodies

THE CASE

You are called from your office to the nursery to see a healthy newborn with a diffuse facial eruption. Her mother, who had a normal pregnancy, labor, and delivery, has a history of Sjögren's syndrome. Both mother and baby have SSA/Ro and SSB/La antibodies. Other laboratory studies, including a complete blood count and liver function tests, and a cardiac examination with an electrocardiogram were normal.

DIAGNOSIS: Neonatal lupus erythematosus

Cutaneous manifestations of NLE occur in 15% to 25% of cases.¹ In most instances, a rash appears between 4 and 6 weeks but may present at birth or not until the infant reaches several months of age.^1,4 The typical rash is characterized by 0.5-cm to 3-cm annular erythematous papules and plaques with atrophy, telangiectasias, dyspigmentation, and central scale.⁴

The rash frequently begins on the scalp and face, and periocular involvement is sometimes prominent, but it may spread to involve the neck, upper trunk, and upper extremities.^1,4,5 It tends to be photosensitive but may appear in non-sun-exposed areas, including the palmar-plantar surfaces and diaper area. The rash is usually transient, lasting a mean duration of 15 to 17 weeks.^1,6 Its disappearance coincides with the clearance of maternal IgG antibodies from the infant's circulation.⁴ However, in 10% to 20% of cases, subtle atrophy, telangiectasias, and pigmentary changes may remain.^1,4

PATHOPHYSIOLOGY

More than 95% of cutaneous cases of NLE involve circulating SSA/Ro antibodies, but there are reported cases of only U1RNP antibodies being present.¹ One study found that cutaneous NLE in an SSA/Ro antibody-exposed infant predicted a 6- to 10-fold risk of a subsequent pregnancy developing cardiac NLE.⁶ Other manifestations may be seen, including petechiae or purpura secondary to thrombocytopenia and jaundice secondary to hepatic involvement.⁷

Neonatal lupus erythematosus is the number one cause of congenital heart block.⁴ Cardiac complications of NLE are associated with significant morbidity and mortality.⁶ Nearly 67% of neonates with cardiac manifestations of NLE require pacemaker placement, and as many as 20% to 30% die.

Approximately 10% of cases of NLE are associated with liver and hematologic involvement.⁸ Hepatic involvement is typically characterized by an asymptomatic elevation in alanine aminotransferase and aspartate aminotransferase, but hyperbilirubinemia, hepatitis, hepatomegaly, splenomegaly, and even liver failure have been reported.^1,8