A 45-year-old man presents to the clinic with a three-day history of a painful, swollen, red lesion on his right lower leg. He initially noticed a small cut after bumping into a table, but over the past few days, the area has become increasingly tender, warm, and swollen. He also reports a low-grade fever and mild fatigue.

His medical history includes type 2 diabetes mellitus, but he has no known allergies or history of skin conditions. He denies recent travel or exposure to unusual insects or animals.

On examination, there is a 5 cm area of erythema, warmth, and induration on the anterior lower leg. A small central area of pustular drainage is present. Regional lymph nodes are mildly enlarged, and his temperature is 38.2°C (100.8°F). There are no signs of necrosis or systemic sepsis, but the findings are suggestive of a bacterial skin infection.

A clinical diagnosis of cellulitis with a possible abscess is made. The patient is started on oral antibiotics (empirical coverage for Staphylococcus and Streptococcus species), instructed on wound care, and advised to monitor for worsening symptoms such as increasing redness, fever, or spreading infection. Due to his diabetes, he is also counseled on proper foot and skin care to prevent future infections.