Overview of Neonatal Lupus
Overview of Neonatal Lupus
NL can present in utero or postnatally. In utero, the diagnosis may be presumptive in a fetus that exhibits any degree of CHB on a fetal echocardiogram. If the mother is known to have an autoimmune disorder, one assumes that the presenting CHB in the fetus is due to the presence of maternal autoantibodies. In utero, CHB begins in the second trimester (Lee, 2009).
Postnatally, NL is most often diagnosed on the basis of the clinical manifestations on the skin. These manifestations may be a different dermatologic presentation than that of the mother (Wisuthsarewong et al., 2011). Based on maternal history, serum antibody levels may be determined to confirm the diagnosis. Persistent neonatal bradycardia on physical examination could signify the presence of CHB. An echocardiogram and Doppler study of the heart could confirm the presence of heart block and any other associated cardiac findings.
A skin biopsy is necessary if the diagnosis of NL is questionable (Pain & Beresford, 2007) or if the maternal diagnosis is suggestive of subacute cutaneous lupus erythematosus (Krishna, 2011). Associated cutaneous findings found on biopsy were noted by several authors. Vacuolation of the epidermal basal layer with an upper dermal lymphocytic infiltrate was noted by Guinovart and colleagues (2012). Laurinaviciene, Christesen, and Bygum (2012) noted lesions consistent with subacute cutaneous lupus erythematosus with few keratinocytes. The authors also noted vacuolar degeneration in the basal cell layer, interstitial perivascular lymphocytic infiltrate, and granular deposits of immunoglobulin M at the dermoepidermal junction. Satter and High (2007) presented two cases of NL with biopsy findings that showed lesions infiltrated with neutrophilic material along with focal vacuolar degeneration with neutrophils in the upper dermis along the dermoepidermal junction. Interstitial lymphocytic infiltrate (Peñate et al., 2009) along with orthokeratosis has been noted, as has lymphohistiocytic infiltrate and scattered necrotic keratinocytes (Sawant, Amladi, Wadhawa, Nayak, & Nikam, 2007).
Neonatal skin rashes are a common finding and complaint for the practitioner who works with infants and children. The task is to separate a rash that is benign from a rash that is indicative of a serious medical concern. Bacterial and viral infections such as in TORCH infections can present as a newborn rash with macules, papules, and vesicle findings. The rash of erythema toxicum and transient neonatal pustular melanosis should be differentiated from the bullous presentation of methicillin-resistant Staphylococcus aureus, epidermolysis bullosa, or other bullous skin lesions. Table 2 lists the differential diagnoses based on presentation of cutaneous lesions.
Diagnosis
NL can present in utero or postnatally. In utero, the diagnosis may be presumptive in a fetus that exhibits any degree of CHB on a fetal echocardiogram. If the mother is known to have an autoimmune disorder, one assumes that the presenting CHB in the fetus is due to the presence of maternal autoantibodies. In utero, CHB begins in the second trimester (Lee, 2009).
Postnatally, NL is most often diagnosed on the basis of the clinical manifestations on the skin. These manifestations may be a different dermatologic presentation than that of the mother (Wisuthsarewong et al., 2011). Based on maternal history, serum antibody levels may be determined to confirm the diagnosis. Persistent neonatal bradycardia on physical examination could signify the presence of CHB. An echocardiogram and Doppler study of the heart could confirm the presence of heart block and any other associated cardiac findings.
A skin biopsy is necessary if the diagnosis of NL is questionable (Pain & Beresford, 2007) or if the maternal diagnosis is suggestive of subacute cutaneous lupus erythematosus (Krishna, 2011). Associated cutaneous findings found on biopsy were noted by several authors. Vacuolation of the epidermal basal layer with an upper dermal lymphocytic infiltrate was noted by Guinovart and colleagues (2012). Laurinaviciene, Christesen, and Bygum (2012) noted lesions consistent with subacute cutaneous lupus erythematosus with few keratinocytes. The authors also noted vacuolar degeneration in the basal cell layer, interstitial perivascular lymphocytic infiltrate, and granular deposits of immunoglobulin M at the dermoepidermal junction. Satter and High (2007) presented two cases of NL with biopsy findings that showed lesions infiltrated with neutrophilic material along with focal vacuolar degeneration with neutrophils in the upper dermis along the dermoepidermal junction. Interstitial lymphocytic infiltrate (Peñate et al., 2009) along with orthokeratosis has been noted, as has lymphohistiocytic infiltrate and scattered necrotic keratinocytes (Sawant, Amladi, Wadhawa, Nayak, & Nikam, 2007).
Differential Diagnosis With Cutaneous Neonatal Lupus
Neonatal skin rashes are a common finding and complaint for the practitioner who works with infants and children. The task is to separate a rash that is benign from a rash that is indicative of a serious medical concern. Bacterial and viral infections such as in TORCH infections can present as a newborn rash with macules, papules, and vesicle findings. The rash of erythema toxicum and transient neonatal pustular melanosis should be differentiated from the bullous presentation of methicillin-resistant Staphylococcus aureus, epidermolysis bullosa, or other bullous skin lesions. Table 2 lists the differential diagnoses based on presentation of cutaneous lesions.