This document discusses lymphangitis and lymphadenitis. Lymphangitis is defined as inflammation of the lymphatic channels that occurs as a result of infection at a site distal to the channel. Common causes include streptococcal bacteria. Symptoms include red streaks on the skin extending from the infection site toward lymph nodes. Treatment involves antibiotics. Lymphadenitis is inflammation of lymph nodes, which can be caused by various bacteria, viruses, fungi or other pathogens. Evaluation may involve imaging and biopsy to determine the cause and guide treatment.