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Syndrome in newborns characterized by congenital heart
block and/or cutaneous lupus erythematosus in the presence of maternal
autoantibodies.
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Estimated to be 1:12,500 live births. An infant born of
an anti-Ro(SSA) antibody-positive mother has a 1:20 chance of developing a
neonatal lupus syndrome.
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No racial or sexual predilection, but there is
an increased frequency of the HLA-DR3 phenotype in mothers of infants with
neonatal lupus.
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Believed to be caused by transplacental passage of
specific autoantibodies (primarily anti-Ro/SSA and anti-La/SSB) from the
mother with systemic lupus erythematosus to the fetus. These autoantibodies
bind to fetal Ro and La autoantigens and induce an inflammatory infiltrate
in the skin or heart. The latter results in scarring with fibrosis and
calcification, causing complete congenital heart block.
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Characteristic skin lesions and/or congenital complete
heart block with positive maternal anti-Ro and anti-Ra antibodies.
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Approximately 50% of infants with neonatal
lupus have characteristic skin lesions, with predilection for involvement
around the eyes—“raccoon eyes” appearance. In the other 50% of
affected infants, cardiac lesions predominate. In approximately 10%, both
cutaneous and cardiac lesions are present. The skin lesions (generalized,
erythematous, nonscaling, sharply demarcated) develop in the first month or
later in life, and they generally disappear by 6 months, which corresponds
to the disappearance of the maternal IgG antibodies from the infant's serum.
Neonatal lupus dermatitis responds to topical steroids. Avoidance of
sunlight exposure is recommended because exacerbation and induction of skin
lesions follow ultraviolet light exposure. Congenital
abnormalities include patent ductus arteriosus, ventricular septal defect,
transposition of the great arteries, atrial septal defect, coarctation of
the aorta, and tetralogy of Fallot. The first cause of mortality (15-35%) and
morbidity of neonates affected with lupus is complete congenital heart block. A
pacemaker is required in one third of infants. Thrombocytopenia and liver
involvement occur but are normally mild and transient.
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Check drug history (steroids,
cardiac drugs). Investigations include ECG, echocardiography, chest
radiography, arterial blood gases, and levels of electrolytes, urea,
creatinine, and hemoglobin. In patients with preexisting permanent
pacemaker, ascertain pacemaker function according to institution protocol. A
magnet or reprogramming device and expertise that can be used to convert the
pacemaker to asynchronous mode should be available. In patients without
preexisting permanent pacemaker, measures and expertise for temporary pacing
(cardiologist, transcutaneous pacing, transesophageal pacing, transvenous
pacing) should be available prior to induction of anesthesia. Chronotropic
drugs (atropine, isoprenaline) should be available.
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When transporting and positioning
patients with temporary pacing devices, take care to prevent accidental
dislodgment of ...