Ruptured lymph gland. Suppurating (pus-producing) ruptured lymph gland in the groin of a man from Africa with the sexually transmitted disease chancroid. This is an infection by the Haemophilus ducreyi bacterium. Chancroid, or soft sore, is a common disease in the tropics. It causes ulcers on the mucous membranes of the genitals and causes an enlargement of the lymph nodes (part of the immune system) in the groin. Treatment is with antibiotic drugs. Tropical infections can be more severe and take longer to heal than elsewhere.