5 | DISCUSSION
An acquired immune-mediated
disorder, NLE is an extraordinary occurrence, caused by maternal IgG
antibodies against Ro/SSA, La/SSB, or U-RNP in the newborn. It occurs in
approximately 1 per 20,000
newborns,1and 2% in offspring of mothers with Sjögren’s
syndrome with an 18 to 20 percent
recurrence rate in subsequent
pregnancies.3
Clinical signs of NLE may include annular skin rash, cytopenia,
hepatitis, and congenital heart block. It is essential to keep track of
these patients over time, as they are more prone to autoimmune disorders
in later childhood or adulthood.4
Confirmation of the diagnosis of NLE can be achieved by considering the
patient’s medical history, conducting a physical examination, and
detecting the presence of specific antibodies in both the fetus and the
mother. While a skin biopsy is helpful, it is not necessary in order to
establish the diagnosis. Other conditions that may need to be considered
when making a differential diagnosis include congenital syphilis, tinea
corporis, sarcoidosis, granuloma annulare, Langerhans histiocytosis,
Sweet syndrome, and urticaria.
While cases of NLE among siblings have been reported,5they typically present with the same or similar manifestations, making
it a rare occurrence due to the increased risk of pregnancy in affected
women. In our cases,
it is very interesting that cutaneous
NLE occurs in two siblings with significantly different cutaneous
manifestations. The various clinical expressions may be attributed to a
different specificity of Anti-Ro autoantibodies among
siblings.6 Additionally, other foeto-maternal factors
including environmental, intrauterine, or genetic influences may affect
the pathogenesis and expression of NLE.7
It is believed that pregnant women who test positive for autoantibodies
to Sjögren’s syndrome autoantigens types A or B are considered to have a
high-risk pregnancy, particularly
those with a prior history of NLE,8 due to the
increased danger of NLE in offspring of future
pregnancies.3
It was deemed highly hazardous for the mother and her unborn child not
to keep track of the fetal PR interval through echocardiogram during
gestation, thus necessitating the implementation of counseling advice,
fetal screening, maternal screening, and prevention or management of
heart disease.8 Current recommendations are to conduct
an echocardiogram weekly between 16-26 weeks’ gestation and biweekly
between 26-32 weeks.
The mainstay of management for
infants with cutaneous manifestations is to actively prevent sun
exposure by utilizing methods such as sunscreen and protective
clothing,9 just like in our cases, both children only
presented with rashes, the key of the management is photoprotection.
The sister followed up for 7 years and the younger brother followed up
for 1 year. So far, neither of the siblings has experienced any
recurrence of skin lesions, and developed any autoimmune diseases. At
present, both siblings are still following up at the outpatient clinic
to monitor biochemical
tests、echocardiogram and ECG.
As global fertility declines, many countries are implementing policies
to stimulate fertility growth. The Chinese government, for instance,
liberalized the two-child policy in 2016,10 and
further liberalized the ”three-child” policy in 2021. This has not
caused a baby boom, but rather a moderate rise in
fertility,11 resulting in more families having a
second
child.2Therefore, it is estimated that the incidence rate of NLE
in siblings
will
increase too, so we should raise the
awareness of NLE in siblings, which is very important for the
monitoring, evaluation, diagnosis and management of NLE.