For discussion of the condition in horses, see Equine Lymphangitis.

Lymphangitis is an inflammation or an infection of the lymphatic channels that occurs as a result of infection at a site distal to the channel. The most common cause of lymphangitis in humans is Streptococcus pyogenes (Group A strep), although it can also be caused by the fungus Sporothrix schenckii. Lymphangitis is sometimes mistakenly called "blood poisoning". In reality, "blood poisoning" is synonymous with sepsis.