You make a diagnosis of definite chancroid
by detecting antigens of Haemophilus ducreyi by PCR.
that’s the way to make them.
Gram stain is not that sensitive.
It’s probable chancroid if a patient presents with one or more genital ulcers
that are painful, and you’ve ruled out syphilis –
no evidence of Treponema pallidum either by dark field,
or their serology is negative.
Or if they have a typical clinical presentation,
and you’ve also thought about herpes simplex and you’ve tested for that,
and the test for herpes simplex is negative –
that would be examples of probable chancroid.
Now in terms of treatment, azithromycin in a single dose is very effective.
Alternatives include ceftriaxone, a single intramuscular dose,
and remember that this is a Gram-negative pleomorphic rod,
and like ceftriaxone works with Haemophilus influenzae.
You wouldn’t be surprised that it also works for Haemophilus ducreyi.
Ditto ciprofloxacin and erythromycin given for 7 days.
And what you would expect in a patient is
that they would be better in 3-7 days.
If they’re not better, then perhaps the diagnosis is not correct.
So what do we do about a patient who
you thought had chancroid but you weren’t able to prove it
and they didn’t get any better?
Well the main thing that you want to rule out is the painful genital infection
due to herpes simplex,
and also an atypical presentation of primary syphilis.
So you would want to rule those 2 things out.
Now in terms of treating the contacts of the patients –
someone who’s had sex with a patient
within 10 days before the onset of symptoms –
they need to be identified and treated.
Even asymptomatic contacts of people you thought had chancroid
should be treated,
and the treatment is simple with 1 gram of azithromycin in a single dose.
That concludes my discussion of chancroid.