Wash the area immediately with strong soap. Application of an antihistamine cream or steroid cream may help with the itching or taking an antihistamine, especially Benadryl may relieve some of the itching. See Poison Control centers for telephone numbers and addresses.
Fatalities are very uncommon.
At worst the individual will be very uncomfortable for a while. A secondary skin infection may develop if the exposed areas are not kept clean. The information provided herein should not be used for diagnosis or treatment of any medical condition. It is provided for your general information and is not a substitute for medical care or supervised medical treatment. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions.