A rash in an infant and his mother

An 11-week-old male infant was irritable and had decreased oral intake and nasal congestion. For six weeks, he had had a rash on the face, scalp, trunk and extremities. The rashes had not responded to asteroid ointment. The mother had a history of eczema. There was thrush in the mouth and a clear nasal discharge. The skin on the face showed erosion and crusted patches on forehead, cheeks, chin and eyebrows, with erythema and some scarring. Depressed lesions were seen in some areas. There were hyperpigmented brown, scaly patches on the left arm, erythematous scaly patches on the right arm, hyperpigmented lesions on chest and legs and plantar erythema and scaling. The rest of the physical examination was normal. Examination of the mother showed that what had been diagnosed as eczema was in fact discoid lupus. The baby was found to have an ANA positive 1:320 and a positive anti-RNP, confirming that he had neonatal systemic lupus erythematosus. Neonatal lupus occurs because of transplacental transmission of IgG autoantibodies from a mother who has lupus. In 50% of cases, the mother is asymptomatic. Other diseases associated with neonatal lupus include Sjogren syndrome, rheumatoid arthritis, or mixed connective tissue disease. Besides skin involvement, there may also be involvement of other organs: heart, liver, spleen and lymph nodes etc. In neonatal lupus, the antibodies most often persist for six months and the eruption clears spontaneously in about 6-12 months.