Differential Diagnoses:
Primary syphilis
Donovanosis (granuloma inguinale)
Herpes simplex virus
Lymphogranuloma venereum
Behçet syndrome
Diagnosis: Chancroid
Learnings: Chancroid (soft chancre or ulcus molle) is a sexually transmitted infection caused by infection with the gram-negative, facultative anaerobic bacillus Haemophilus ducreyi.
Although chancroid is a major cause of genital disease in Southeast Asia, sub-Saharan Africa, and Latin America, it is not common in the United States. The World Health Organization estimated that there were 7 million annual cases in 2001, but definitive epidemiologic data are generally not available because of underreporting and difficulty isolating H. ducreyi in the laboratory.
Sex workers and people from a low socioeconomic class are at higher risk for the disease. Chancroid is a significant risk factor for heterosexual transmission of HIV.
The incubation period is 3 to 7 days. Prodromal symptoms and systemic symptoms are rare. The disease begins as a papule in the genital area and becomes a shaggy, painful ulceration within days. Untreated lesions can become quite destructive.
As opposed to chancroid, primary syphilis typically has a firm, painless ulcer with a border that is not undermined. Syphilis has a longer incubation period (3 weeks, versus 1 week for chancroid). The ulcer from syphilis will heal with or without treatment. A chancroid ulcer will not heal without treatment; it will enlarge.
What to Look For
Ulcers will be soft and tender, painful, and yellowish in color with a dirty surface, and will have an undermined border and surrounding erythema. The most common site for ulcers to appear is in the inner aspect of the foreskin. Other sites include the coronal sulcus and the frenulum. It is rare to find extragenital lesions. Patients will often have one or more tender inguinal lymph nodes called buboes.
Acknowledgment: Image courtesy of Logical Images, Inc. (www.VisualDx.com/JUCM)