A 28-year-old man who has recently emigrated from Nigeria presents with a penile ulcer. It initially started as a papule which later progressed to become a painful ulcer with an undermined ragged edge. Examination of the testes was unremarkable but tender inguinal lymphadenopathy was noted.
What is the most likely diagnosis?
Correct Answer A:
Genital ulcers:
A diagnosis of chancroid is more likely than lymphogranuloma venereum as the ulcer is painful. Whilst herpes simplex is obviously more common the description of the ulcer is very characteristic of chancroid. Painful inguinal lymphadenopathy is present in around 50% of patients.
STI: ulcers:
Genital herpes is most often caused by the herpes simplex virus (HSV) type 2 (cold sores are usually due to HSV type 1). Primary attacks are often severe and associated with fever whilst subsequent attacks are generally less severe and localized to one site.
Syphilis is a sexually transmitted infection caused by the spirochaete Treponema pallidum. Infection is characterized by primary, secondary and tertiary stages. A painless ulcer (chancre) is seen in the primary stage.
The incubation period= 9-90 days.
Chancroid is a tropical disease caused by Haemophilus ducreyi. It causes painful genital ulcers associated with inguinal lymph node enlargement.
Lymphogranuloma venereum is caused by Chlamydia trachomatis. Typically infection comprises of three stages:
Other causes of genital ulcers:
*Previously called Calymmatobacterium granulomatis.
A 24-year-old man presents with a three day history of painful ulcers on the shaft of his penis and dysuria. He has had no similar previous episodes. A clinical diagnosis of primary genital herpes is made.
What is the most appropriate management?
Correct Answer E: Oral antiviral therapy is indicated for primary genital herpes infections, even if the presentation is delayed for up to 5 days.
Herpes simplex virus:
There are two strains of the herpes simplex virus (HSV) in humans: HSV-1 and HSV-2. Whilst it was previously thought HSV-1 accounted for oral lesions (cold sores) and HSV-2 for genital herpes it is now known there is considerable overlap.
Features:
Management:
Which one of the following tests is most likely to remain positive in a patient with syphilis despite treatment?
Correct Answer E:
Syphilis: investigation:
Treponema pallidum is a very sensitive organism and cannot be grown on artificial media. The diagnosis is therefore usually based on clinical features, serology and microscopic examination of infected tissue.
Serological tests can be divided into:
Cardiolipin tests:
Treponemal specific antibody tests:
Causes of false positive cardiolipin tests:
Which of the following antibiotics is predominately bactericidal?
Correct Answer C:
Antibiotics: bactericidal vs. bacteriostatic:
Bactericidal antibiotics:
Bacteriostatic antibiotics:
A health care assistant sustains a needlestick injury whilst taking blood from a patient who is known to be HIV positive.
Following thorough washing of the wound what is the most appropriate management?
Correct Answer C: Post-exposure prophylaxis for HIV: oral antiretroviral therapy for 4 weeks.
Post-exposure prophylaxis:
Hepatitis A:
Hepatitis B:
Hepatitis C:
HIV:
Varicella zoster:
Estimates of transmission risk for single needlestick injury:
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