Chancroid or soft chancre is an acute STI caused by Haemophilus ducreyi.
At the site of inoculation an erythematous papular lesion forms which then breaks down into an ulcer. The ulcer frequently has a necrotic base, a ragged edge, bleeds easily and is painful. Several ulcers may merge to form giant serpiginous lesions. Ulcers appear most commonly on the prepuce and frenulum in men and can erode through tissues. In women the most commonly affected site is the vaginal entrance and the perineum. The lesions in women sometimes go unnoticed. At the same time, inguinal lymphadenopathy develops (usually unilateral) and can progress to form large buboes which suppurate.
Genital herpes is one of the most common STIs world-wide. The peak incidence is in 16- to 24-year-olds of both sexes. Infection may be either primary or recurrent. Transmission occurs during close contact with a person who is shedding virus. Most genital herpes is due to type 2. Genital contact with oral lesions caused by HSV-1 can also produce genital infection.
Susceptible mucous membranes include the genital tract, rectum, mouth and oropharynx. The virus has the ability to establish latency in the dorsal root ganglia by ascending peripheral sensory nerves from the area of inoculation. It is this ability which allows for recurrent attacks.
Asymptomatic infection has been reported but is rare. Primary genital herpes is usually accompanied by systemic symptoms of varying severity including fever, myalgia and headache. Multiple painful shallow ulcers develop which may coalesce. Atypical lesions are common. Tender inguinal lymphadenopathy is usual. Over a period of 10-14 days the lesions develop crusts and dry. In women with vulval lesions the cervix is almost always involved. Rectal infection may lead to a florid proctitis. Neurological complications can include aseptic encephalitis and/or involvement of the sacral autonomic plexus leading to retention of urine.
Recurrent attacks occur in a significant proportion of people following the initial episode. Precipitating factors vary, as does the frequency of recurrence. A symptom prodrome is present in some people prior to the appearance of lesions. Systemic symptoms are rare in recurrent attacks.
The clinical manifestations in immunosuppressed patients (including those with HIV) may be more severe, asymptomatic shedding increased, and recurrences occur with greater frequency.
Lymphogranuloma venereum (LGV)
Chlamydia trachomatis types LGV 1, 2 and 3 are responsible for this sexually transmitted infection. It is endemic in the tropics, with the highest incidences in Africa, India and South East Asia.
The primary lesion is a painless ulcerating papule on the genitalia occurring 7-21 days following exposure. It is frequently unnoticed. A few days to weeks after this heals, regional lymphadenopathy develops. The lymph nodes are painful and fixed and the overlying skin develops a dusky erythematous appearance. Finally, nodes may become fluctuant (buboes) and can rupture. Acute LGV also presents as proctitis with peri-rectal abscesses. The destruction of local lymph nodes can lead to lymphoedema of the genitalia.