Shankroid: causes, symptoms, diagnosis, treatment

Chancroid (synonyms: third venereal disease, soft chancre, venereal ulcer) is found in countries of Africa, Asia, America. However, due to the growth of international relations, tourism, the infection may be introduced.

Chancroid is endemic in some areas of the United States, and isolated outbreaks occur. Chancroid has been shown to be a cofactor in HIV transmission, and high rates of HIV infection have been reported among patients with chancroid in the United States and other countries. About 10% of patients with chancroid may be co-infected with T. pallidum and HSV.

Causes and pathogenesis of chancroid. The causative agent of chancroid is the streptobacillus Haemophilis Dukreу, described for the first time by Ferrary and simultaneously by O. V. Peterson in 1887, Ducrey in 1889, then N. Krefting in 1892, M. Unna in 1892. The streptobacillus is a short (1.5-2 μm), thin (0.5-0.6 μm) in diameter rod with several rounded ends and a constriction in the middle. It is located singly or parallel transversely in the form of chains (5-25 rods), from which it received the name streptobacillus. The causative agent in appearance resembles eights, dumbbells, less often - a type of cocci. At the initial stages of the disease, the rod is located extracellularly, and in late forms - intracellularly. It does not contain endotoxins and does not release toxins. The microbe quickly dies when heated (at a temperature of 50° C - within 5 minutes). In pus, the bacilli retain virulence for up to 6-8 days at room temperature, up to 10 days - at low temperature.

Epidemiology of chancroid. Infection occurs through direct contact, exclusively during sexual intercourse. The pathogen is located on the genitals, less often on the inner thigh, perianally, rarely on the cervix and vagina. Chancroids have been described on the oral mucosa and fingers. Rarely, the infection is transmitted through objects. Men are more often affected, and women can be carriers of the bacilli. There is no immunity after the disease. The incubation period for men is 2-3 days, sometimes 2-3 weeks, for women - from 2-3 weeks to 3-5 months.

Symptoms of chancroid. At the site of microbe introduction, a small bright red spot develops. The next day, a papule forms over the spot, then a blister with transparent contents develops. The contents of the blister become cloudy and a purulent liquid forms. After 3-4 days, the pustule opens and an ulcer forms, slightly elevated above the level of healthy skin, prone to peripheral growth and reaching up to 1.0-1.5 cm. The ulcer is round, irregular, its edges are eaten away, undermined, soft, with an uneven soft bottom. The bottom is covered with a yellowish-gray coating. The edges of the ulcer are elevated and have an acute inflammatory rim. Palpation shows that the base of the ulcer has a soft consistency. Ulcers in the heading groove are exceptionally compacted. Streptobacilli are detected from the purulent discharge of the chancroid ulcer. In men, the ulcer is painful, while in women, the pain may be absent or insignificant. Ulcers may increase in number due to autoinoculation. The primary ulcer may be located in the center, and "daughter" soft ulcers form around it. Progression stops after 2-4 weeks, purulent discharge, the number of ulcers and the inflammatory process gradually decrease, as a result, the ulcers granulate and scars form. Without complications, chancroid heals in 1-2 months.

In addition to typical forms of chancroid, other atypical varieties are distinguished:

• elevated chancroid, in which the base of the ulcer is raised due to granulation, as a result of which the ulcer is slightly raised above the surface of the surrounding skin;
• serpentinous chancroid, characterized by slow peripheral growth of one of the edges of the ulcer;
• follicular chancroid, which occurs as a result of the penetration of the pathogen into the excretory ducts of the sebaceous glands or hair follicles, which leads to the formation of single and multiple nodules, in the center of which are deep ulcers with purulent discharge;
• funnel-shaped chancroid - occurs rarely, on the coronary groove of the penis, is limited, in the form of a cone with a compaction, there is an ulcer at the base, and the top penetrates into the subcutaneous tissue;
• diphtheritic chancroid, in which the ulcer is deep, the bottom is covered with a dense dirty yellow fibrinoid coating. It lasts for a long time;
• impetiginous chancroid, characterized by the appearance of blisters that persist for a long time. The contents dry out, forming a crust. After removing the crust, the following is exposed: a deep ulcer;
• herpetic chancroid, clinically similar to simple vesicular lichen. It is prone to autoinoculation. Inguinal lymphadenitis develops. Streptobacilli are found in the contents of the vesicles;
• nodular chancroid - a compaction is palpated at the base of the lesion;
• chancroid, characterized by the appearance of painful cracks with a pronounced reaction. Localized in the folds of the skin;
• gangrenous chancroid, which is formed as a result of penetration of anaerobic microbes and fusospirillosis. Ulcers in this case grow peripherally, deep tissues disintegrate, resulting in ulcers with undermined edges, and under them - deep passages, which in men can lead to the destruction of the cavernous bodies and, as a result, to amputation of the penis with severe bleeding;
• phagedenic chancroid, which differs from gangrenous by the absence of a demarcation line, and the progression of gangrene inward and along the periphery. Chills occur, body temperature rises, and sometimes sepsis develops.
• mixed chancroid, developing as a result of penetration of streptobacillus and pale trepopema simultaneously or sequentially. In this case, chancroid appears first, and then syphilis. Formation of a chancroid ulcer occurs in 2-3 days, and a syphilitic ulcer - in 3-4 weeks. Detection of pathogens is important.

Complications of chancroid. Lymphangitis is a common complication of chancroid, as the lymphatic vessels of the back of the penis in men and the labia in women are involved in the process. The vessel becomes a dense cord, not connected to the skin, running from the ulcer to the lymph nodes. The skin becomes hyperemic and swollen, but dense nodules are formed. They can dissolve or ulcerate.

Bubo. Observed in 40-50% of patients. Occurs 2-4 weeks after streptobacillus penetrates regional lymph nodes, most often in the inguinal lymph nodes. Development of bubo is enhanced by physical exertion and the use of cauterizing drugs. One or more lymph nodes are involved in the pathological process. With the development of periadenitis, the lymph nodes can merge with each other and form conglomerates. The skin above the node is hyperemic, edematous, painful, body temperature rises, and malaise occurs. Later, the inflammation subsides, the center softens and fluctuation phenomena occur. The skin becomes thinner and deteriorates, a large amount of pus mixed with blood is released from the resulting cavity, sometimes the cavity granulates and a scar forms. Often, the bubo turns into a large ulcer, often surrounded by new lesions (chancrotic bubo). In some victims, the process is sluggish, with the formation of cold abscesses, deep, fistulous passages (goitrous bubo) are formed. Adenopathy may occur several weeks or months after treatment.

Phimosis. Develops as a result of the formation of multiple ulcers on the inner layer of the foreskin or along its edge, which increases the size of the penis due to swelling of the foreskin. The skin becomes hyperemic, the opening of the preputial sac narrows, and copious purulent discharge, increased body temperature, and pain are observed.

Paraphimosis. Rarely develops, there is a forced wrapping of the edematous foreskin behind the head, which compresses the penis in the head groove and leads to a violation of blood circulation. The head of the penis swells, increases in volume, the color becomes bluish, severe pain develops, necrosis of the head and foreskin can form.

Laboratory diagnostics. To detect streptobacilli, ulcers and purulent discharge from opened or unopened lymph nodes (buboes) are necessary. For this, the areas from which the material will be taken are cleaned, applied to glass and stained using the Romanovsky-Giemsa method or methylene blue; they are negative when stained according to Gram. The preparation should be stained after a slight warming. If the results are negative, the autoinoculation method can be used by applying pus or pieces rejected from ulcerous foci of necrotic tissue.

Definitive diagnosis of chancroid requires isolation of pure culture of H. ducreyi on special media that are not commercially available; even with these media, sensitivity is less than 80% and usually lower. A probable diagnosis (for both treatment and surveillance) can be made if a patient has one or more painful genital ulcers and (a) there is no evidence of T. pallidum infection by dark-field examination of ulcer exudate or by serologic testing for syphilis at least 7 days after ulcer onset and (b) the appearance and location of the ulcers and regional lymphadenopathy, if present, are typical of chancroid and the HSV test is negative. The combination of a painful ulcer and tender lymph nodes in the groin (which are found in one third of patients) confirms the presence of chancroid, and if this combination is accompanied by suppuration of the lymph nodes, it is almost pathognomonic. It is expected that PCR will soon become a widely available method for diagnosing chancroid.

Treatment of chancroid. Antibiotics and sulfonamides are used. Azithromycin (azimed) is prescribed at 1.0 g orally once or ceftriaxone 250 mg intramuscularly once, or erythromycin 500 mg 4 times a day for 7 days, or ciprofloxacin 500 mg 2 times a day for 3 days.

Successful treatment of chancroid results in a cure, resolution of clinical symptoms, and prevention of transmission of the infection to others. In case of extensive lesions, scarring may occur despite successful treatment.

Recommended schemes

Azithromycin 1 g orally once

Or Ceftriaxone 250 mg intramuscularly (IM) once

Or Ciprofloxacin 500 mg orally 2 times a day for 3 days

Or Erythromycin base 500 mg orally 4 times a day for 7 days

NOTE: Ciprofloxacin is contraindicated in pregnant or lactating women and in individuals under 18 years of age.

All four regimens are effective for the treatment of chancroid in patients with HIV infection. Azithromycin and ceftriaxone have the advantage of being administered as a single dose. Several isolates with resistance to either ciprofloxacin or erythromycin have been reported from around the world.

Other considerations for patient management

Treatment of HIV-infected patients and patients who have not been circumcised may be less effective than in patients who are not infected with HIV or who have been circumcised. When chancroid is diagnosed, HIV testing should be performed simultaneously. Serologic tests for syphilis and HIV should be repeated after 3 months if the initial results of these tests were negative.

Follow-up observation

Patients should be re-examined 3 to 7 days after initiation of therapy. With successful treatment, ulcers improve symptomatically within 3 days and objectively within 7 days of initiation of therapy. If clinical improvement is not observed, the physician should consider the following possibilities: a) misdiagnosis, b) co-infection with another STD, c) the patient is infected with HIV, d) non-adherence to treatment, or e) the causative strain of H. ducreyi is resistant to the prescribed drug. The time required for complete healing depends on the size of the ulcer; a large ulcer may require more than 2 weeks of treatment. In addition, healing is slower in some uncircumcised men whose ulcer is located under the foreskin. Fluctuant lymph nodes take longer to resolve clinically than the ulcer to heal, and even with successful treatment, drainage may be required. Incision and drainage of buboes may be preferable to aspiration of the contents with a syringe because drainage requires fewer subsequent procedures, although aspiration is a simpler procedure.

Management of sexual partners

Persons who have had sexual contact with patients with chancroid within 10 days before the onset of clinical symptoms in these patients should be examined and treated, even if they do not have symptoms of the disease.

Special Notes

Pregnancy

The safety of azithromycin in pregnant and lactating women has not been established. Ciprofloxacin is contraindicated during pregnancy. There have been no reports of adverse pregnancy outcomes or fetal abnormalities with chancroid.

HIV infection

Patients who are co-infected with HIV should be closely monitored. These patients may require longer courses of therapy than those recommended in this guideline. Ulcer healing may be delayed in HIV-infected patients, and any given regimen may be ineffective. Because data on the therapeutic efficacy of the recommended ceftriaxone and azithromycin regimens in HIV-infected patients are limited, they may be used in these patients if follow-up is available. Some experts suggest using a 7-day course of erythromycin in HIV-infected patients.

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