Although all scorpions in North America sting, most are relatively harmless. The stings usually cause only localized pain with minimal swelling, some lymphangitis with regional lymphadenopathy, increased skin temperature, and tenderness around the wound.
A significant exception in North America is the bark scorpion (Centruroides sculpturatus, also known as C. exilicauda), present in Arizona, in New Mexico, and on the California side of the Colorado River. This species is venomous and can cause more serious injury and illness.
Initial symptoms are immediate pain and sometimes numbness or tingling over the involved part. Swelling is usually absent, and there are few skin changes. Serious symptoms, most common among children, include
Restlessness
Muscle spasms
Abnormal and random head, neck, and eye movements
Anxiety and agitation
Sialorrhea and diaphoresis
In adults, tachycardia, hypertension, increased respirations, weakness, muscle spasms, and fasciculations may predominate. Respiratory difficulties are rare in both age groups.
C. sculpturatus stings have resulted in death in children lt; 6 years and in hypersensitive people.