A 62-year-old woman has an acute onset of the disease: high temperature of 39.8°C, chills, intense headache, and aching body. She complains of nausea and one episode of vomiting. 18 hours later, her right inguinal lymph nodes became enlarged and sharply painful. After another 6 hours, she developed edema of the right shin and skin hyperemia with irregular-shaped clear margins. What is the most likely diagnosis in this case?