My Mother Got This Rash On Her Leg Today. She

My mother got this rash on her leg today. She says it doesn't really itch. She recently had sand fly bites on the same leg. She works outside in the garden (we live in the woods) every day. What could this be?? She doesn't have insurance so I'm trying to gauge how serious this is. She has type 1 diabetes.

http://tinypic.com/r/314b21g/8

Age: 59
Sex: F
Height: 5'1
Weight: 110
Race: Caucasian
Duration of Complaint: One Day
Location: NJ / Lower Leg
Existing Medical Issues: Type 1 Diabetes
Current Medications: Insulin and Lantis