Summary about Disease
Neonatal lupus is a rare autoimmune condition that affects infants. It occurs when maternal antibodies, specifically anti-Ro/SSA and/or anti-La/SSB antibodies, cross the placenta and affect the fetus. It's important to note that mothers who have these antibodies may or may not have diagnosed lupus themselves. Most infants with neonatal lupus do not have permanent damage, and symptoms usually resolve within the first six to eight months as the maternal antibodies are cleared from the baby's system. However, cardiac involvement, specifically congenital heart block, can be permanent and requires ongoing medical management.
Symptoms
The most common symptoms include:
Skin rash: Typically appears as circular or oval, slightly raised, reddish lesions, often on the face and scalp.
Congenital heart block: Slow heart rate. This is the most serious manifestation.
Liver problems: Elevated liver enzymes.
Blood abnormalities: Low white blood cell count (leukopenia) and/or low platelet count (thrombocytopenia).
Causes
Neonatal lupus is caused by the transfer of maternal autoantibodies (anti-Ro/SSA and/or anti-La/SSB) across the placenta to the fetus. These antibodies react with fetal tissues, leading to inflammation and tissue damage. The mother may or may not have diagnosed lupus or another autoimmune disease, such as Sjögren's syndrome. Sometimes, mothers are completely asymptomatic and only discover they have these antibodies when their child is diagnosed.
Medicine Used
Corticosteroids: Used to treat skin rashes and liver inflammation.
Intravenous immunoglobulin (IVIG): Can be used in cases of low platelet counts.
Pace maker: Permanent pacemaker implantation is required to treat congenital heart block.
Other immunosuppressants: May be considered in severe cases.
Is Communicable
Neonatal lupus is not communicable. It is not contagious and cannot be spread from person to person. It is caused by the transfer of maternal antibodies to the fetus.
Precautions
For mothers with anti-Ro/SSA and/or anti-La/SSB antibodies:
Close monitoring during pregnancy: Regular fetal echocardiograms to detect heart block.
Avoidance of certain medications during pregnancy: Consult with a rheumatologist and obstetrician.
Photoprotection: Protecting the infant from sunlight to prevent skin rashes.
Regular follow-up with pediatric cardiologist if congenital heart block is present.
How long does an outbreak last?
Most symptoms of neonatal lupus, except for congenital heart block, are temporary and resolve within six to eight months, as the maternal antibodies gradually disappear from the infant's system. Congenital heart block, if present, is permanent and requires ongoing management.
How is it diagnosed?
Clinical evaluation: Based on the presence of characteristic symptoms.
Maternal antibody testing: Testing the mother's blood for anti-Ro/SSA and anti-La/SSB antibodies.
Infant antibody testing: Testing the infant's blood for the same antibodies.
Electrocardiogram (ECG): To assess heart rhythm and detect heart block.
Echocardiogram: To evaluate heart structure and function in utero and postnatally.
Liver function tests: To assess liver involvement.
Complete blood count (CBC): To check for blood abnormalities.
Skin biopsy: Performed when rashes are present and diagnosis is in question.
Timeline of Symptoms
During pregnancy: Congenital heart block can be detected as early as 16-24 weeks gestation.
At birth or shortly after: Skin rash, liver problems, and blood abnormalities may be present.
Within the first few months: Symptoms typically peak and then gradually resolve as maternal antibodies clear.
Beyond 6-8 months: Most symptoms resolve, except for permanent heart block, if present.
Important Considerations
Mothers with anti-Ro/SSA and/or anti-La/SSB antibodies have an increased risk of having another child with neonatal lupus.
Genetic counseling may be helpful to understand the risks.
Early diagnosis and management are crucial to minimize potential complications.
Multidisciplinary care involving rheumatologists, cardiologists, dermatologists, and neonatologists is often necessary.
Even in the absence of diagnosed autoimmune disease, mothers with these antibodies should be monitored for the development of autoimmune conditions over time.