Final answer:
Based on the symptoms described, the 88-year-old patient most likely has cellulitis, a bacterial infection of the skin and tissues beneath the skin, characterized by redness, exudate, warmth at the site, and fever.
Step-by-step explanation:
The 88-year-old patient presenting with sudden pain and tenderness to the left hip, areas of redness, exudate, warmth, and a fever likely has a condition known as cellulitis. Cellulitis is a bacterial infection of the skin and tissues beneath the skin. The clinical symptoms including redness, warmth, and exudate, along with the fever, are characteristic of infection rather than a broken hip, which typically does not present with signs of infection like redness and warmth, or rheumatoid arthritis, which is a chronic autoimmune condition. Osteomyelitis is also a possible diagnosis considering it is an infection of the bone, which can present with similar symptoms as cellulitis but is distinguished by deeper, bone-related pain and confirmed by imaging and other diagnostic tools. The information provided leans more towards cellulitis, since it is consistent with the combination of superficial signs (redness and warmth) and systemic symptoms (fever).