Chancroid: Symptoms, Types, Causes and Treatment

Chancroid is a lesser-known but important sexually transmitted infection that can have significant health impacts, especially in regions where access to medical care and laboratory diagnosis is limited. Characterized by painful genital ulcers, this disease is most often seen in developing countries but can occur anywhere. Understanding the symptoms, types, causes, and available treatments is crucial for both healthcare providers and the general public in controlling its spread and minimizing complications.

Symptoms of Chancroid

Chancroid often presents with distinct and sometimes alarming symptoms, making early recognition vital. The infection commonly causes painful sores on the genitalia, which can be accompanied by swollen lymph nodes in the groin region. Its symptoms are frequently confused with other sexually transmitted infections, so a comprehensive understanding is essential for timely diagnosis and management.

Symptom	Description	Frequency/Severity	Source(s)
Ulcers	Painful, soft, irregular genital sores	Common and defining	1 2 4
Lymphadenitis	Swollen, tender groin lymph nodes	33–50% of cases	1 2 3 4
Bubo	Enlarged, sometimes suppurative nodes	Severe presentations	1 2 3
Exudate	Yellow/gray necrotic or purulent base	Often present	4

Table 1: Key Symptoms

Painful Genital Ulcers

The hallmark of chancroid is the development of one or more painful, soft ulcers on the genitalia. These ulcers have irregular, undermined edges and are often surrounded by inflamed tissue. Unlike some other sexually transmitted ulcers, chancroid lesions are usually tender and may bleed when touched or rubbed. The base of the ulcer is typically covered with a yellow or gray necrotic exudate, adding to the discomfort and risk of secondary infection 1 2 4.

Inguinal Lymphadenitis and Bubo Formation

A significant portion of patients—ranging from one-third to one-half—develop regional lymphadenitis. This condition is characterized by swollen, tender lymph nodes in the groin, known as buboes when they become particularly large or suppurative. Buboes may rupture, discharging pus, and require additional medical intervention 1 2 3 4.

Additional Symptoms

• Exudate: The ulcer base often contains a yellow or gray, necrotic, purulent discharge 4.
• Bleeding: Ulcers may bleed upon contact or trauma 4.
• Pain on Urination: If the ulcer is located near the urethra, contact with urine can be particularly painful 3.

Differential Diagnosis

Because genital ulcers can arise from several causes—including syphilis, herpes simplex virus, granuloma inguinale, and others—laboratory tests are crucial for accurate diagnosis. Chancroid should always be considered in cases of painful, rapidly developing genital ulcers, especially when accompanied by inguinal swelling 3 4.

Types of Chancroid

While chancroid is most commonly discussed as a single disease entity, its clinical presentation can vary. Recognizing these variations helps in distinguishing it from other genital ulcer diseases and in providing the most appropriate care.

Type	Distinguishing Feature	Prevalence/Context	Source(s)
Typical Chancroid	Single/multiple painful ulcers	Most common	1 2 4
Phagedenic	Rapidly spreading, necrotic	Severe, rare	1
Mixed Infection	Coexists with other STIs	Not uncommon	3 4 13
Chronic	Persistent, slow-healing ulcers	Rare, in immunocompromised	1 13

Table 2: Types of Chancroid

Typical Chancroid

In most cases, chancroid presents as soft, painful ulcers that develop rapidly after exposure. The ulcers may be single or multiple and are localized on the genitalia. Pain and tenderness are prominent features, distinguishing them from the usually painless ulcers of primary syphilis 1 2 4.

Phagedenic (Necrotizing) Chancroid

A more severe, less common form is phagedenic chancroid, where the ulcer rapidly enlarges and tissue necrosis is pronounced. This aggressive variant can cause significant tissue destruction and requires urgent medical intervention 1.

Mixed Infections

Chancroid can coexist with other sexually transmitted infections, such as syphilis, herpes simplex virus, or even vaginal candidiasis, as described in rare case reports 3 4 13. This overlap can complicate diagnosis and treatment, making thorough laboratory evaluation necessary.

Chronic Chancroid

Occasionally, especially in immunocompromised individuals (such as those with HIV), chancroid may present as chronic, slow-healing ulcers. These cases are more challenging to treat and are associated with higher rates of complications 1 13.

Causes of Chancroid

Understanding the etiology of chancroid is essential not only for diagnosis but also for prevention strategies. The disease is caused by a specific bacterium and spreads through particular routes, with some populations being more at risk.

Cause	Details	Notes/Implications	Source(s)
Haemophilus ducreyi	Gram-negative coccobacillus bacterium	Fastidious, hard to culture	1 2 5 6
Sexual transmission	Direct skin/mucosal contact	Main transmission route	1 2 4 8
Co-infections	With other STIs (HIV, syphilis, HSV)	Increases transmission risk	6 8
Antimicrobial resistance	Increasing concern	Impacts treatment choices	5 10 11

Table 3: Causes of Chancroid

Haemophilus ducreyi

Chancroid is caused by the bacterium Haemophilus ducreyi, a gram-negative coccobacillus. This organism is considered fastidious, meaning it requires specific conditions to grow in the laboratory, making culture-based diagnosis challenging 1 2 5 6. Microscopically, it appears as a small, gram-negative rod that is sometimes seen in "school of fish" arrangements in stained smears 3.

Transmission

Chancroid spreads almost exclusively through sexual contact, typically via direct skin or mucosal contact with ulcerative lesions of an infected individual. The risk of transmission increases with the presence of open ulcers, which facilitate the entry of the bacterium 1 2 4 8.

Role of Co-infections

Chancroid often coexists with other sexually transmitted infections, particularly syphilis and herpes simplex virus. Its presence has been shown to significantly increase the risk of HIV transmission, likely due to the disruption of mucosal barriers and the presence of inflammatory cells at the ulcer site 6 8.

Antimicrobial Resistance

There is a growing concern about antimicrobial resistance in H. ducreyi, which has shown the ability to acquire resistance genes from both gram-positive and gram-negative organisms. This resistance complicates treatment and highlights the need for ongoing surveillance and updated therapeutic guidelines 5 10 11.

Treatment of Chancroid

Effective treatment of chancroid is essential to alleviate symptoms, prevent complications, and reduce the transmission of both chancroid and other infections like HIV. Multiple antibiotic regimens are available, with some being more user-friendly than others.

Treatment	Dosage/Duration	Efficacy/Notes	Source(s)
Erythromycin	500 mg orally, 4x daily for 7 days	Standard, high cure rates	1 2 12 13
Azithromycin	1 g orally, single dose	Effective, convenient	12
Ciprofloxacin	500 mg, single dose or 3 days	Highly effective, few failures	11 13
Ceftriaxone	250 mg intramuscular, single dose	Decreased efficacy in some	10
Other antibiotics	Fleroxacin, trimethoprim-sulfamethoxazole	Used in some regimens	9 11
Supportive care	Saline dressings, pain management	Adjunctive, improves comfort	4

Table 4: Treatment Options

Mainstay Antibiotic Therapy

• Erythromycin: Traditionally, erythromycin has been the cornerstone of chancroid treatment, administered as 500 mg orally four times daily for a week. It remains a highly effective regimen, with cure rates exceeding 90% 1 2 12 13.
• Azithromycin: A single, 1-gram oral dose of azithromycin offers similar efficacy to erythromycin, with the added advantage of better patient compliance due to its single-dose administration 12.
• Ciprofloxacin: Both single-dose (500 mg) and three-day regimens (500 mg twice daily) of ciprofloxacin have been shown to be highly effective, especially in areas where resistance to other drugs is developing 11 13.

Alternative and Adjunctive Treatments

• Ceftriaxone: Once considered a reliable single-dose intramuscular therapy (250 mg), ceftriaxone's efficacy has declined in some regions, particularly among HIV-infected patients 10.
• Other Agents: Fleroxacin and trimethoprim-sulfamethoxazole have been used with success in certain settings, but local resistance patterns may affect their utility 9 11.
• Supportive Care: In addition to antibiotics, saline dressings and pain management are important to promote healing and patient comfort, especially when ulcers are extensive or when co-infections, such as vaginal candidiasis, are present 4.

Special Considerations

• HIV Co-infection: Treatment failures are more common among those co-infected with HIV, possibly due to altered immune responses and higher rates of antimicrobial resistance. These patients may require longer or alternative antibiotic regimens 9 10 12 13.
• Follow-Up: Clinical improvement should be assessed within 3–7 days of starting therapy. Persistent or worsening ulcers warrant re-evaluation for alternative diagnoses, resistance, or mixed infections.

Conclusion

Chancroid, though less common in developed countries, remains a significant public health concern in many parts of the world due to its painful symptoms, potential complications, and role in facilitating HIV transmission. Early recognition, accurate diagnosis, and effective treatment are essential for controlling this infection.

Key Takeaways:

• Chancroid is characterized by painful, soft genital ulcers and often by swollen groin lymph nodes (buboes) 1 2 4.
• It is caused by Haemophilus ducreyi, a gram-negative bacterium transmitted via sexual contact 1 2 5 6.
• Clinical types range from typical ulcers to more severe, necrotizing, or chronic forms, and may coexist with other STIs 1 4 13.
• Diagnosis can be challenging due to the difficulty in culturing the organism and its similarity to other ulcerative diseases 1 3 5.
• Effective treatment options include erythromycin, azithromycin, and ciprofloxacin, but resistance patterns and co-infections (especially with HIV) affect treatment success 10 11 12 13.
• Supportive care and prompt management are vital to prevent complications and limit the spread of both chancroid and HIV 4 6 8.

Staying informed about chancroid’s symptoms, types, causes, and treatments enables individuals and healthcare providers to act swiftly—protecting health, reducing transmission, and improving outcomes for those affected.