Lymphangitis is an inflammation of one or more lymphatic vessels, often caused by streptococcal infection. Streptococcus bacteria usually enter the lymphatic vessels (part of the body’s immune system) through abrasions or traumatic wounds on the arms or legs. Typically, streptococcal infections of the skin and subcutaneous tissue spread to the lymphatic vessels. Occasionally, it can be caused by staphylococcus or other bacteria. The skin of the affected arm or leg will form irregular, tender red bands. These bands usually extend from the infected area to a group of lymph nodes, such as the groin or armpits. These lymph nodes may also become enlarged and tender. Common symptoms include fever, chills, increased heart rate, and headache. Sometimes these symptoms occur before the red band appears. If the infection spreads from the lymphatic system to the bloodstream, it can spread throughout the body at an alarming rate. Inflammation of the skin or tissue over the diseased lymphatic vessels, and occasionally skin ulcers, can also occur, and sometimes the bacteria enter the blood system (bacteremia). Lymphangitis can be diagnosed on the basis of its typical clinical presentation. Blood tests typically show an increased number of white blood cells that can fight infection. It is generally difficult for the physician to identify the causative organism unless it has spread into the blood system or pus can be removed from the affected wound. Most patients improve rapidly with antibiotics that are sensitive to staphylococci and streptococci (e.g., dicloxacillin, nafcillin, or benzocillin).