[Neonatal lupus in an infant of a mother followed up for dermatomyositis: medical images].

Neonatal lupus is rare. It is due to the transmission of maternal autoantibodies across the placenta during pregnancy. We here report the case of a 2-month old female infant treated for erythematous macular cutaneous lesions on the face and the trunk. Her mother was followed up for dermatomyositis diagnosed on the basis of clinical lesions, muscle weakness and elevation in muscle enzyme levels. However she had not underwent antinuclear antibody test (ANA). Clinical examination showed atrophic erythematous lesions distributed like butterfly wings on both sides of the nasal pyramid, satellite lesions on the front, with red hair. The remainder of the physical examination was unremarkable. Laboratory tests were not performed because infant's parents also refused the biopsy. These lesions suggested seborrheic dermatitis, rosacea or atopic dermatitis. However, rosacea is very rare in infants and usually affects fair-skinned people. In seborrheic dermatitis, lesions are not atrophic. The age of onset of atopic dermatitis is usually 3 months. Lesions regressed in 15 days under dermocorticoid therapy.