Neonatal lupus: causes, signs in the baby and what happens next

Neonatal lupus erythematosus (NLE) is an acquired autoimmune condition of newborns. A clinical review describes a clinical spectrum of skin, cardiac and systemic abnormalities in babies whose mothers have autoantibodies against Ro/SSA and La/SSB, and less commonly U1-ribonucleoprotein. A second paper explains that it results from passive transfer of maternal autoantibodies to the baby.

This is different from lupus as it is diagnosed in older children and adults. The baby does not develop lupus through their own immune system in the usual way: the problems are driven by the mother's antibodies, which cross the placenta and gradually disappear from the baby's circulation after birth. That is why the skin, liver and blood features usually clear, while damage to the heart's electrical system, if it occurs, may not.

There are no UK patient information pages on neonatal lupus from the NHS or UK lupus charities that could be read for this guide, so this page relies on two published medical reviews from outside the UK. UK care is delivered by obstetric, fetal medicine, paediatric and rheumatology teams; ask your own team about local arrangements.

The review says approximately 98% of affected infants have maternal transfer of antibodies against Ro/SSA, La/SSB or, less commonly, U1-RNP, but that only 1 to 2% of mothers with these antibodies have babies with the condition, whether or not the mother has symptoms. It says the amount of maternal antibody, rather than simply its presence, is associated with fetal tissue injury, and that other factors such as genetics may be involved.

Many mothers do not know they carry the antibodies. The reviews say that between 40 and 60% of mothers, or about half, are completely without symptoms at the time of diagnosis, and become aware of the antibodies when a fetal heart rhythm problem or a newborn skin rash is found. The remainder may have systemic lupus, Sjogren syndrome, rheumatoid arthritis or an undifferentiated autoimmune disorder. The review found no association with paternal autoimmune disease.

The review says the most common features, in decreasing order of frequency, affect the skin, the heart and the liver, and that one or more systems may be involved.

• Rash: ring-shaped red patches, often on the scalp, neck or face and sometimes with redness around the eyes, which may be present at birth but often appears within the first weeks. The review says it resembles the rash of subacute cutaneous lupus rather than the malar rash of adult lupus, and that sunlight or phototherapy can bring it on or worsen it. It typically lasts weeks or months and resolves spontaneously as maternal antibodies disappear.

• Heart: conduction abnormalities from first-degree to complete (third-degree) heart block, and sometimes cardiomyopathy. Complete heart block may be noted as a slow heartbeat before birth or at birth, and heart failure is a recognised complication in the newborn period.

• Liver: raised liver enzymes or jaundice appearing a few weeks or months after birth, with mild enlargement of the liver or spleen. The review says most liver or blood involvement is transient and resolves within 4 to 6 months.

• Blood: low platelets, low red cells or low neutrophil counts, usually from around the second week, resolving by about the end of the second month.

Diagnosis rests on the typical features together with maternal and infant antibody tests. A case report with literature review described a baby whose rash was initially thought to be a fungal infection until blood tests showed anti-Ro/SSA and anti-La/SSB antibodies in both mother and child, and noted that rashes of this kind are often misdiagnosed as infection or eczema, particularly when the mother is without symptoms.

Heart block can be picked up before birth. The review notes it may present as a slow heart rate noticed in the womb, and says babies with cardiac involvement need regular monitoring of heart function and the need for a pacemaker, with serial echocardiograms. It also says babies with the condition should be managed at a specialist centre with a multidisciplinary team.

Mothers who are found to have these antibodies are usually followed by obstetric and rheumatology teams. The review emphasises serial ultrasound and echocardiography in later pregnancies for those with a previous affected child.

The review says treatment of skin, blood, spleen and liver involvement is supportive because it is usually self-limited and resolves without intervention. Avoiding sun and ultraviolet exposure is advised to reduce the rash and residual skin changes. The case report describes using a mild topical steroid but notes that its efficacy has not been established.

Heart block is managed differently. The review says a pacemaker is often necessary for those who cannot compensate for a slow heart rate, and that no standard therapy for heart block detected in the womb has been established. It describes steroid treatment of the mother as having been tried but says definitive recommendations require further trials. It reports that hydroxychloroquine use in mothers with lupus has been associated with a lower rate of neonatal lupus.

For skin, liver and blood features the outlook is good: the review says the rash remits within the first year in almost all cases in parallel with the clearance of maternal antibodies, though mild skin changes such as telangiectasia or changes in pigment can persist. The outlook with heart block depends on its severity. One report cites a mortality rate of 20% in neonates with heart block despite pacemaker implantation, and survivors usually need long-term cardiac follow-up.

The reviews note that children who have had neonatal lupus may be at increased risk of developing an autoimmune or rheumatic condition later, though one study cited found no babies with the condition went on to develop systemic lupus during long-term follow-up. For future pregnancies, the review reports a risk of recurrence of congenital heart block of about 15% and the risk of neonatal lupus in a subsequent pregnancy being higher than in a first pregnancy, which is why pre-pregnancy advice and close monitoring are recommended.

If you have lupus or Sjogren syndrome and are planning a pregnancy, ask your rheumatologist or obstetric team about antibody testing and a monitoring plan. If your baby has a rash and you know you carry these antibodies, tell the midwife, GP or health visitor straight away.