Picture of the Month—Diagnosis FREE

A 2-month-old, white, male infant had a 1-month history of a rash that began on the left face and spread to involve the scalp and right lower abdomen. According to his mother, the lesions appeared to be exacerbated by sun exposure. Prenatal and medical history were unremarkable. There was no family history of rheumatologic or autoimmune disease. Aside from the skin eruption noted, the results of the remainder of the physical examination were normal with no evidence of cardiac abnormalities or hepatosplenomegaly. A complete blood cell count with differential, liver enzyme profile, and a basic chemistry panel were all normal, and a skin fungal culture was negative. Antinuclear antibody (titer of 1:320) and anti-La/SSB antibody were both positive, but surprisingly, anti-Ro/SSA antibody was negative. Complete cardiac evaluation results were normal, including a normal electrocardiogram and echocardiogram. Although his mother was clinically asymptomatic, she also had a positive antinuclear antibody and anti-La/SSB antibody but negative anti-Ro/SSA antibody and negative double-stranded DNA. By 4 months of age, all of the cutaneous lesions had resolved spontaneously with aggressive sun protection, and no new clinical symptoms or physical findings were noted.

Neonatal lupus erythematosus was first described in a newborn in 1954 by McCuistion and Schoch,¹ and it may occur as infrequently as 1 in 20 000 births.² It is an uncommon, passively acquired autoimmune disease associated with the transplacental passage of maternal autoantibodies, in most cases anti-Ro/SSA and/or anti-La/SSB antibodies.² These transplacentally acquired maternal autoantibodies are believed to cause cell injury leading to the development of clinical disease.² Mothers of infants with neonatal lupus may have a known autoimmune disease such as lupus erythematosus, Sjögren syndrome, or mixed connective tissue disease; however, a sizable proportion of mothers can also be clinically asymptomatic. Owing to the subtle and varied clinical presentation of neonatal lupus, a diagnosis can be difficult to make.

The clinical features of neonatal lupus can include cutaneous, cardiac, hepatic, and hematologic abnormalities. The skin eruption may be present at birth or can present during the first several weeks of life, most commonly on the head and neck, with frequent accentuation in the periorbital distribution.^3- 4 Classically, the cutaneous lesions are annular erythematous plaques with scale that may be exacerbated by sun exposure.^3- 4 The rash is often misdiagnosed as tinea corporis or atopic dermatitis.⁴ The lesions usually resolve spontaneously over several months, but they occasionally may leave residual atrophy or telangiectasia. The most severe and life-threatening clinical manifestation of neonatal lupus is third-degree congenital heart block, which can be detected in utero during the second or third trimester.² Hepatobiliary and hematologic involvement may be asymptomatic and detected only through laboratory evaluation during the first several months of life.^5- 6 Rarely, severe liver failure may occur in the neonatal period.⁷ Although neurologic abnormalities are not a clinical feature of neonatal lupus, transient asymptomatic brain abnormalities have been detected on computed tomographic scan in several infants with neonatal lupus.⁸

Infants and their mothers will usually have positive anti-Ro/SSA antibodies, will less commonly have positive anti-La/SSB antibodies, and will rarely have a positive anti-U1RNP antibody.^2,6 Other laboratory abnormalities detected during infancy can include anemia, thrombocytopenia, neutropenia, and elevation of hepatic transaminases, γ-glutamyltransferase, or conjugated bilirubin.^5- 7

All infants with suspected neonatal lupus should receive laboratory screening for the presence of autoantibodies and hematologic or hepatic involvement as well a thorough cardiac evaluation. Neonates with congenital heart block may require pacemaker implantation. Except for those infants with congenital heart block, clinical symptoms are usually transient and resolve by age 6 to 9 months.^4- 5 Often, only aggressive broad-spectrum (UV-A and UV-B) photoprotection and clinical and laboratory monitoring are required during infancy.² Infants and children do not appear to be at an increased risk of developing autoimmune disease as a direct result of their history of neonatal lupus; however, they should be followed up closely throughout childhood and adolescence since their overall risk of rheumatologic disease may be increased relative to the general population because of their familial predisposition.⁹ Asymptomatic mothers of infants with neonatal lupus are at risk of developing rheumatologic disease in the future, and any subsequent pregnancy should be monitored closely.^4- 6

Correspondence: Kimberly A. Horii, MD, Section of Dermatology, Children's Mercy Hospital, 2401 Gillham Rd, Kansas City, MO 64108 (kahorii@cmh.edu).

Accepted for Publication: August 1, 2005.