Neonatal Lupus

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An otherwise healthy 5-week-old infant with erythematous plaques predominantly on the face and scalp presented to our dermatology clinic. The mother had been diagnosed with lupus erythematosus 2 years earlier but her disease was quiescent. Neonatal lupus is a rare condition associated with transplacental transfer of IgG anti-SSA/Ro and anti-SSB/La antibodies from the mother to the fetus. Active connective tissue disease in the mother does not have to be present and in fact is often absent. Although the cutaneous, hematologic and hepatic manifestations are transient, the potential for permanent heart block makes it necessary for this to be carefully ruled out. As in this case, the dermatologist may be the one to make the diagnosis and should be aware of the clinical presentation, work-up, and management of this important disease.



Clinical synopsis

A 5-week-old baby girl was referred to our clinic by her primary pediatrician for an acute erythematosus eruption that had began 10 days earlier. The clinical presentation was initially a red papule on the left cheek, which rapidly evolved into numerous papules and plaques on the face, scalp, trunk, and extremities. The patient's mother reported no problems with her pregnancy or delivery and that the baby had no other medical problems. The baby had no recent sick contacts, was eating normally, and was otherwise doing well. Initially the mother stated that she had no other medical problems, but later recalled that a physician once told her she had systemic lupus erythematosus (SLE) but that her condition was quiescent and she was not currently taking any medicines. There was no other known collagen vascular disease in the family. The baby was not followed for possible complications of SLE during the pregnancy.


Figure 1 Figure 2

Physical examination revealed an irritable but consolable and interactive baby girl in no acute distress. Her skin examination was notable for several well-demarcated erythematosus, scaly, hyperpigmented plaques. The lesions were concentrated on the scalp and face and with similar plaques were scattered on the trunk and lower extremities (Figs. 1 and 2). There was no mucosal involvement.

Given our high index of suspicion for neonatal lupus, we consulted cardiology to rule out congenital heart block. The electrocardiogram revealed normal sinus rhythm with normal axis and intervals; an echocardiogram did not identify significant abnormalities. Complete blood cell count, electrolytes, and liver function studies were all normal. The patient's serum was positive for anti-SSA/Ro and anti-SSB/La antibodies. With cardiac involvement ruled out, the mother was reassured that the cutaneous lesions would resolve and was given a mild topical steroid to apply to the lesional skin. The infant's lesions cleared at approximately 4.5 months of age. She required no further treatment and continued to do well. The mother was counseled about the risks of neonatal lupus occurring in subsequent pregnancies and was instructed to notify her obstetrician of her history so that appropriate screening tests would be performed.


Comment

Neonatal lupus is a rare condition attributed to passively acquired autoantibodies (particularly anti-SSA/Ro, anti-SSB/La antibodies) and characterized by cardiac, cutaneous, hematologic, and hepatic manifestations. Mothers of patients with neonatal lupus may have active systemic lupus erythematosus or Sjogren syndrome, or they may be asymptomatic [1]. The characteristic lesions are erythematous, annular plaques with a tendency to involve the scalp, face, and periorbital region often causing a raccoon-eyes appearance [2]. Cutaneous manifestations often present during the first or second month, but can be present at birth. The lesions are transient, resolving with the clearance of maternal autoantibodies from the neonatal circulation at approximately 6 months of age [3].

The greatest concern when making the diagnosis of neonatal lupus is the risk of congenital heart block, which occurs in 10 percent of the patients with neonatal lupus [4]. Congenital heart block can be diagnosed in-utero and once established it is irreversible [5]. The heart block is thought to result from the deposition of anti-SSA/Ro antibody at the atrioventricular node, which leads to fibrosis and calcification [6]. A recent study by Stea et al., showed that sera from mothers with lupus who gave birth to a child without neonatal lupus had higher anti-idiotypic antibody activity compared to mothers with a child with neonatal lupus, suggesting that the idiotypic antibodies may block pathogenic antibodies in the maternal sera [7]. Pregnant women with known systemic lupus erythematosus should undergo frequent monitoring of the fetal heart rate and weekly ultrasonography beginning at 16-17 weeks of gestation up to 26 weeks and then every other week until 34 weeks [5]. In any new case of neonatal lupus, an electrocardiogram should be performed to rule out a cardiac conduction deficit (e.g., heart block) and an echocardiogram should be performed to rule out cardiac malformations or cardiomyopathy.

Hematologic abnormalities may occur with neonatal lupus and thus all patients should have a complete blood count to rule out thrombocytopenia, leukopenia, anemia, and pancytopenia. Because hepatic abnormalities may occur, including hepatitis with elevated transaminase levels, liver function studies should also be performed.

A skin biopsy is rarely needed to make the diagnosis the diagnosis of neonatal lupus. The typical findings on histologic examination are hyperkeratosis with follicular plugging overlying an interface dermatitis with basalar vacuolar changes. Direct immunoflourescence demonstrates granular IgG deposition at the dermal-epidermal junction and, occasionally, IgM and/or C3 deposition.

Children with neonatal lupus do not have an increased risk for developing systemic lupus erythematosus [8]. However, the child born to a mother with SLE may be at an increased risk for developing some type of autoimmune disorder and thus, these children should be closely monitored by their pediatrician. Treatment of cutaneous lesions generally requires no more than mild topical steroids and general moisturizing.

 
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