Diffuse muscular haemorrhage as presenting sign of juvenile systemic lupus erythematosus and lupus anticoagulant hypoprothrombinaemia syndrome.

Lupus anticoagulants are closely related to systemic lupus erythemathosus (SLE) and to thrombotic events. We describe a 12 year-old girl with a bilateral intramuscular haemorrhage of the gastrocnemius muscles as her main initial presentation of juvenile SLE. Laboratory work-up revealed lupus anticoagulant-hypoprothrombinaemia syndrome (LAHS) with very low levels of factor II due to autoantibodies. She showed a good initial clinical and laboratory response to prednisone therapy, however steroid dependency developed. To the best of our knowledge, this is the first case reported of juvenile SLE presenting with LAHS.