Sickle cell anemias are chronic hemolytic diseases that may induce three types of acute accidents: severe anemia, severe bacterial infections, and ischemic vasoocclusive accidents (VOA) caused by sickle-shaped red blood cells obstructing small blood vessels and capillaries. Many diverse complications can occur.

A focal lesion of a single peripheral nerve. Damage to a sensory nerve is accompanied by sensory impairment of all modalities in the affected anatomic distribution.