Now let me search the medical library for relevant content on diabetic skin conditions and metformin-related rashes in parallel.

I found a very relevant section in Andrews' Diseases of the Skin and Fitzpatrick's on diabetic skin manifestations and Dermatology 2-Volume Set on diabetic dermopathy. Let me read the most relevant sections now.

I found a very detailed and relevant section in Fitzpatrick's on Diabetes and skin. Let me continue reading that section.

Excellent — I now have very rich content from both Fitzpatrick's Dermatology and Dermatology 2-Volume Set. Let me also fetch a relevant clinical image and read the granuloma annulare / necrobiosis lipoidica section.