After an incubation period of one day to two weeks, chancroid begins with a small bump that becomes an ulcer within a day of its appearance. The ulcer characteristically:
Ranges in size dramatically from 3 to 50 mm (1/8 inch to two inches) across
Is painful
Has sharply defined, undermined borders
Has irregular or ragged borders
Has a base that is covered with a gray or yellowish-gray material
Has a base that bleeds easily if traumatized or scraped
In more specific terms, the CDC's standard clinical definition for a probable case of chancroid includes all of the following:
Patient has one or more painful genital ulcers. The combination of a painful ulcer with tender adenopathy is suggestive of chancroid; the presence of suppurative adenopathy is almost pathognomonic.
No evidence of Treponema pallidum is indicated by dark-field examination of ulcer or by a serologic test for Syphilis performed at least 7 days after the onset of ulcer.
The clinical presentation is not typical of disease caused by human herpesvirus 2 (Herpes Simplex Virus), or result of culture for HSV is negative.
About half of infected men have only a single ulcer. Women frequently have four or more ulcers, with fewer symptoms. The ulcers appear in specific locations, such as the coronal sulcus of the uncircumcised glans penis in men, or the fourchette and labia minora in women.
Common locations in women
In women, the most common location for ulcers is the labia majora. "Kissing ulcers" may develop. These are ulcers that occur on opposing surfaces of the labia. Other areas such as the labia minora, perineal area, and inner thighs may also be involved. The most common symptoms in women are dysuria (pain with urination) and dyspareunia (pain with intercourse).
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.