Erb's palsy - Who is to blame and what will happen?

Erb's palsy is initially frightening. The infant's arm hangs limply from the shoulder with flexion of the wrist and fingers due to weakness of muscles innervated by cervical roots C5 and C6. Risk factors are macrosomia (large baby) and shoulder dystocia. However, Erb's palsy may occur following cesarian section. The experience of the delivering physician may not influence the risk of Erb's palsy (0.9 to 2.6 per 1000 live births). Differential diagnosis includes clavicular fracture, osteomyelitis and septic arthritis. Fortunately, the rate of complete recovery is 80% to 96%, especially if improvement begins in the first two weeks. Recommended treatment includes early immobilization followed by passive and active range of motion exercises (although there is no proof that any intervention is effective). For the few infants with no recovery by three to five months, surgical exploration of the brachial plexus may improve the outcome. Three infants with Erb's palsy who illustrate variations in the evolution of this disorder are presented.