<s>[INST] Hello doctor, My father is 65 years old. He seems to have developed some patches on his skin. They are blackish red and also seem to have some pus. He is a diabetic and currently under medication for diabetes, heart and urine issues. [/INST] Hi. I have seen the picture. (attachment removed to protect patient identity). It is diabetic dermopathy with bacterial infection. Skin lesions like carbuncle, ecthyma are common in diabetics. Diabetic microangiopathy is responsible for diabetic dermopathy. Usually, they appear on legs but may occur on forearm (as in our case). Post-inflammatory hyperpigmentation are seen on forearm of long-standing diabetic patients. Also, faulty insulin injection techniques cause induration, scar formation, keloids, and abscess formation. The treatment is control of diabetes. Follow the adage do no harm. Potent topical steroid like Tenovate cream at night for 15 days can be tried (under occlusion). Focus should on preventing ulceration. Fucibet cream (Fusidic acid and Betamethasone) twice daily for 10 days. Use Cetaphil moisturizing lotion for 20 days and tablet Zifi 200 mg (Cefixime) twice daily for five days. </s>