Unusual aetiology of isolated lower motor neuron facial palsy: systemic lupus erythematosus presenting with cranial nerve palsy and nephritis.

A 20-year-old woman presented with common cold symptoms was found to have a left-sided facial droop. On examination, peripheral facial nerve palsy was confirmed. Subsequent testing showed nephrotic range proteinuria and positive serologies including antinuclear antibody and anti-smith antibody. Kidney biopsy showed stage III lupus nephritis. Treatment with pulse steroids along with mycophenolate mofetil for her lupus nephritis resulted in concomitant improvement of her facial palsy.