Chancroid
Chancroid ( ) is a bacterial sexually transmitted infection characterized by painful sores on the genitalia. Chancroid is known to spread from one individual to another solely through sexual contact. However, there have been reports of accidental infection through another route which is by the hand. While uncommon in the western world, it is the most common cause of genital ulceration worldwide. Signs and symptoms. These are only local and no systemic manifestations are present. The ulcer characteristically: About half of infected men have only a single ulcer. Women frequently have four or more ulcers, with fewer symptoms. "The ulcers are  typically confined to the genital region most of the time""." The initial ulcer may be mistaken as a "hard" chancre, the typical sore of primary syphilis, as opposed to the "soft chancre" of chancroid. Approximately one-third of the infected individuals will develop enlargements of the inguinal lymph nodes, the nodes located in the fold between the leg and the lower abdomen. Half of those who develop swelling of the inguinal lymph nodes will progress to a point where the nodes rupture through the skin, producing draining abscesses. The swollen lymph nodes and abscesses are often referred to as buboes . Complications. Sites For Chancroid Lesions Causes. Chancroid is a bacterial infection caused by the fastidious Gram-negative streptobacillus "Haemophilus ducreyi". This pathogen is highly infectious"." It is a disease found primarily in developing countries, most prevalent in low socioeconomic groups, associated with commercial sex workers. Chancroid, caused by "H. ducreyi" has infrequently been associated with cases of Genital Ulcer Disease in the US but has been isolated in up to 10% of genital ulcers diagnosed from STD clinics in Memphis and Chicago. Infection levels are very low in the Western world, typically around one case per two million of the  population (Canada, France, Australia, UK and US). Most individuals diagnosed with chancroid have visited countries or areas where the disease is known to occur frequently, although outbreaks have been observed in association with crack cocaine use and prostitution. Chancroid is a risk factor for contracting HIV, due to their ecological association or shared risk of exposure, and biologically facilitated transmission of one infection by the other. Approximately 10% of people with chancroid will have a co-infection with syphilis and/or HIV. Pathogenesis. "H. ducreyi" enters skin through microabrasions incurred during sexual intercourse. "The incubation period of H.ducreyi infection is 10  to 14 days after which there is progression of the disease""." A local tissue reaction leads to development of erythomatous papule, which progresses to pustule in 4–7 days. It then undergoes central necrosis to ulcerate. Diagnosis. Variants. Some of clinical variants are as follows. Laboratory findings. From bubo pus or ulcer secretions, "H. ducreyi" can be identified using special culture media; however, there is a <80% sensitivity. PCR-based identification of the organisms is available, but none in the United States are FDA-cleared. Simple, rapid, sensitive and inexpensive antigen detection methods for "H. ducreyi" identification are also popular . Serologic detection of "H. ducreyi" uses outer membrane protein and lipooligosaccharide. "Most of the time, the diagnosis is based on presumptive approach using the symptomatology which in this case includes multiple painful genital ulcers""." Differential diagnosis. Despite many distinguishing features, the clinical spectrums of following diseases may overlap with chancroid: Practical clinical approach for this STI as Genital Ulcer Disease is to rule out top differential diagnosis of Syphilis and Herpes and consider empirical treatment for Chancroid as testing is not commonly done for the latter. Comparison with syphilis. There are many differences and similarities between the conditions syphilitic chancre  and chancroid: Prevention. Chancroid spreads in populations with high sexual activity, such as prostitutes. Use of condom, prophylaxis by azithromycin, syndromic management of genital ulcers, treating patients with reactive syphilis serology are some of the strategies successfully tried in Thailand. Also, treatment of sexual partners is advocated whether they develop symptoms or not as long as there was unprotected sexual intercourse with the patient within 10 days of developing the symptoms. Treatment. For the initial stages of the lesion, cleaning with soapy solution is recommended and sitz bath may be beneficial. Fluctuant nodules may require aspiration. Treatment may include more  than one prescribed medication. Antibiotics. Macrolides are often used to treat chancroid. The CDC recommendation is either a single oral dose (1 gram) of azithromycin, a single IM dose (250 mg) of ceftriaxone, oral (500 mg) of erythromycin three times a day for seven days, or oral (500 mg) of ciprofloxacin twice a day for three days. Due to a paucity of reliable empirical evidence it is not clear whether macrolides are actually more effective and/or better tolerated than other antibiotics when treating chancroid. Data is limited, but there have been reports of ciprofloxacin and erythromycin resistance. Aminoglycosides such as  gentamicin, streptomycin, and kanamycin has been used to successfully treat chancroid; however aminoglycoside-resistant strain of "H. ducreyi" have been observed in both laboratory and clinical settings. Treatment with aminoglycosides should be considered as only a supplement to a primary treatment. Pregnant and lactating women, or those below 18 years of age regardless of gender, should not use ciprofloxacin as treatment for chancroid. Treatment failure is possible with HIV co-infection and extended therapy is sometimes required. Prognosis. Prognosis is excellent with proper treatment. Treating sexual contacts of affected individual helps break cycle of infection. Follow-up. Within 3–7 days  after commencing treatment, patients should be re-examined to determine whether the treatment was successful. Within 3 days, symptoms of ulcers should improve. Healing time of the ulcer depends mainly on size and can take more than two weeks for larger ulcers. In uncircumcised men, healing is slower if the ulcer is under the foreskin. Sometimes, needle aspiration or incision and drainage are necessary. Epidemiology. Although the prevalence of chancroid has decreased in the United States and worldwide, sporadic outbreaks can still occur in regions of the Caribbean and Africa. Like other sexually transmitted diseases, having chancroid increases the risk  of transmitting and acquiring HIV. History. Chancroid has been known to humans since time of ancient Greeks. Some of important events on historical timeline of chancre are: