Chancroid (Haemophilus ducreyi)
Haemophilus ducreyi is a short, slender, gram-negative bacillus with rounded ends.
Chancroid is a rare sexually transmitted infection (STI) in the US and other resource-rich countries, occurring primarily in occasional, local epidemics. Chancroid is a common cause of genital ulcers in resource-poor areas of Asia, Africa, and the Caribbean. Like other STIs causing genital ulcers, chancroid increases risk of HIV transmission.
Symptoms and Signs of Chancroid
After an incubation period of 3 to 7 days, small, painful papules appear on the genitals and rapidly break down into shallow, soft, painful ulcers with ragged, undermined edges (ie, with overhanging tissue) and a red border. Ulcers vary in size and often coalesce. Deeper erosion occasionally leads to marked tissue destruction.
The inguinal lymph nodes form a bubo (enlarged and tender group of regional lymph nodes). They sometimes become matted together, fluctuant, or suppurative, in some cases forming an abscess. The skin over the abscess may become red and shiny and may break down to form a sinus. The infection may spread to other areas of skin, resulting in new lesions. Phimosis, urethral stricture, and urethral fistula may result from chancroid.