Insulin injection lipodystrophy

Many patients whit type 1 diabetes mellitus may presented with depressed areas of skin at the sites of insulin injection due to lipoatrophy......!!
Lipodystrophy or lipoatrophy is a recognized complication of Insulin injection due to loss of the adipose tissue layer at the sites of injection (prevalence of 3.6%).
Axial magnetic resonance imaging of the right thigh showed Lipoatrophy of a 14-year-old girl with a 20-month history of type 1 diabetes mellitus

The pathogenesis remains unknown, but possible mechanisms include immune reaction to insulin or excipients of the injection solution, injury from cold insulin, or trauma from repeated local injections.