Review Question - QID 220794

This patient, who presents with multiple painful ulcers and inguinal lymphadenopathy in the setting of unprotected sexual intercourse, most likely has chancroid. Chancroid is a sexually transmitted infection caused by Haemophilus ducreyi and is treated with azithromycin or ceftriaxone.

H. ducreyi is a highly infectious bacterium that causes chancroid. This organism is introduced via microabrasions in the skin during sexual intercourse. It presents after an incubation period of 3-10 days with an erythematous papule that rapidly evolves into a painful ulcer with a deep purulent base that may have gray or yellow exudate. This is followed by painful unilateral inguinal lymphadenopathy that may suppurate or rupture 1-2 weeks later. A probable clinical diagnosis can be made in patients with multiple painful genital ulcers with a clinical course typical for chancroid, and in whom infection with Treponema pallidum and herpes simplex virus have been ruled out. Laboratory confirmation of chancroid can be made with culture or nucleic acid amplification testing. Empiric treatment options for chancroid are either azithromycin or ceftriaxone.

Romero et al. reviewed the use of antibiotics for the treatment of chancroid. They discuss how there is little evidence to suggest a difference between cure rates for macrolides and other antimicrobial treatments such as ceftriaxone. They recommend that azithromycin be considered a first-line treatment agent for chancroid.

Figure/Illustration A is a clinical photograph demonstrating multiple deep ulcers with erythematous bases (red circle). These findings are commonly seen in chancroid infection.

Incorrect Answers:
Answer 2: Doxycycline can be used to treat lymphogranuloma venereum (LGV) and granuloma inguinale. LGV is caused by infection with Chlamydia trachomatis serotypes L1-L3 and presents with small, painless genital ulcers and large painful fluctuant lymphadenopathy. Granuloma inguinale presents with painless, progressive ulcers with granulation-like tissue, as well as nodular lesions that resemble lymph nodes (pseudobuboes).

Answer 3: Metronidazole can be used to treat extraintestinal Entamoeba histolytica amebiasis. In rare cases, painful perianal or perineal ulceration may be the only manifestation of amebiasis. This infection may be sexually transmitted in endemic areas. It would not be expected to cause painful regional lymphadenopathy.

Answer 4: Penicillin is the treatment of choice for syphilis. Syphilis classically presents with a singular painless genital ulcer and non-tender regional lymphadenopathy. Due to the exceedingly low incidence of chancroid in the developed world and risk of coinfection with syphilis, empiric penicillin G is recommended in suspected cases of chancroid. Penicillin V is not used in the treatment of sexually transmitted infections.

Answer 5: Trimethoprim-sulfamethoxazole (TMP-SMX) can be used to treat urinary, respiratory, and intestinal infections. TMP-SMX has activity against Methicillin-resistant Staphylococcus aureus (MRSA) and is commonly used as an oral agent against MRSA infections. Although TMP-SMX was previously a first-line treatment for chancroid, H. ducreyi has developed increasing resistance to this medication.

Bullet Summary:
Chancroid presents with painful ulcers with a deep purulent base and painful inguinal lymphadenopathy and can be treated with azithromycin or ceftriaxone.