Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Cellulitis ?
    ### Response:
    Cellulitis is an infection of the skin and deep underlying tissues. Group A strep (streptococcal) bacteria are the most common cause. The bacteria enter your body when you get an injury such as a bruise, burn, surgical cut, or wound.    Symptoms include       - Fever and chills    - Swollen glands or lymph nodes    - A rash with painful, red, tender skin.
    