#Lymphangitis.#—­Inflammation of peripheral lymph vessels usually results from some primary source of pyogenic infection in the skin.  This may be a wound or a purulent blister, and the streptococcus pyogenes is the organism most frequently present. Septic lymphangitis is commonly met with in those who, from the nature of their occupation, handle infective material.  A gonococcal form has been observed in those suffering from gonorrhoea.

The inflammation affects chiefly the walls of the vessels, and is attended with clotting of the lymph.  There is also some degree of inflammation of the surrounding cellular tissue—­peri-lymphangitis.  One or more abscesses may form along the course of the vessels, or a spreading cellulitis may supervene.

The clinical features resemble those of other pyogenic infections, and there are wavy red lines running from the source of infection towards the nearest lymph glands.  These correspond to the inflamed vessels, and are the seat of burning pain and tenderness.  The associated glands are enlarged and painful.  In severe cases the symptoms merge into those of septicaemia.  When the deep lymph vessels alone are involved, the superficial red lines are absent, but the limb becomes greatly swollen and pits on pressure.

In cases of extensive lymphangitis, especially when there are repeated attacks, the vessels are obliterated by the formation of new connective tissue and a persistent solid oedema results, culminating in one form of elephantiasis.

Treatment.—­The primary source of infection is dealt with on the usual lines.  If the lymphangitis affects an extremity, Bier’s elastic bandage is applied, and if suppuration occurs, the pus is let out through one or more small incisions; in other parts of the body Klapp’s suction bells are employed.  An autogenous vaccine may be prepared and injected.  When the condition has subsided, the limb is massaged and evenly bandaged to promote the disappearance of oedema.

Tuberculous Lymphangitis.—­Although lymph vessels play an important role in the spread of tuberculosis, the clinical recognition of the disease in them is exceptional.  The infection spreads upwards along the superficial lymphatics, which become nodularly thickened; at one or more points, larger, peri-lymphangitic nodules may form and break down into abscesses and ulcers; the nearest group of glands become infected at an early stage.  When the disease is widely distributed throughout the lymphatics of the limb, it becomes swollen and hard—­a condition illustrated by lupus elephantiasis.

Syphilitic lymphangitis is observed in cases of primary syphilis, in which the vessels of the dorsum of the penis can be felt as indurated cords.

In addition to acting as channels for the conveyance of bacterial infection, lymph vessels frequently convey the cells of malignant tumours, and especially cancer, from the seat of the primary disease to the nearest lymph glands, and they may themselves become the seat of cancerous growth forming nodular cords.  The permeation of cancer by way of the lymphatics, described by Sampson Handley, has already been referred to.