If you've been reading here very long, you know me - I get my undergarments in a major twist every time I hear of someone's doctor telling them there is such a thing as HS without bacteria, or of someone's doctor using a medication besides antibiotics on HS. I'm sure that's still hard for some of us to understand because we've probably been let down by a number of antibiotics if we still have HS, and that's certainly true even in my case.

But always curious where this idea of HS without bacteria ever got started in the first place, so I started retracing the steps again a little.

To my knowledge there are only two medical books devoted to HS... (See how easy it is to be a grumpy HS expert? You only have to read two books and you get to say, "Shut up, I've read every book there is on this subject!!!") :-)

And even if we were lucky enough to get our doctors to read one of these two books, they might end up a little confused...

The book on HS by van der Zee
repub.eur.nl/pub/32091/111207_Zee-Hindrik-Hessel-van-der.pdf
informs us that

"At first sight the clinical aspects of HS do suggest infection. But
results of bacterial cultures, despite the volume of discharge, are often negative or do only yield skin commensal microbiota67,68. In a retrospective study, axillary bacterial cultures from HS patients demonstrated that the most prevalent aerobic bacteria species were Staphylococcus aureus, Streptococcus pyogenes, and Pseudomonas aeruginosa, the most frequent anaerobic bacteria were Streptostreptococcus species, Prevotella species, microaerophilic
streptococci, Fusobacterium species, and Bacteroides species67. However, these bacteria were collected by epidermal swabs which
were potentially contaminated with skin commensals. Later, this contamination factor was circumvented in a study aspirating pus from the deeper parts of HS lesions68. Using this method bacteria were cultured in only half of the samples68. The most frequently cultured bacteria were S. aureus and coagulase-negative staphylococci (S.
epidermidis and S. hominis), so again skin commensals68."

And the book organized by Gregor Jemec (here is the chapter on HS bacteriology) http://eknygos.lsmuni.lt/springer/197/86-94.pdf
informs us that

"Despite the volume of the discharge the HS lesions are often found to be sterile [29, 33], but sometimes a large variety of microorganisms
can be isolated from the sinuses, particularly staphylococci, streptococci, Gram-negative rods, and anaerobic bacteria (Table 1.2)."

So naturally the reader wants to interpret this to mean that often, up to half the time, HS lesions have no bacteria in them.

Unless your doctor does a second thing that they might not actually be able to take the time to do, which is follow up the references here, they might not notice that BOTH OF THESE SOURCES may be mincing up a study by Jemec et al with the study by Lapins et al in order to be able to make it sound like this.

van der Zee ref 67 = Jemec ref 29 =
The bacteriology of hidradenitis suppurativa.
Jemec GB, Faber M, Gutschik E, et al (1996)
Dermatology 193:203206

van der Zee ref 68 = Jemec ref 33 =
Coagulase-negative staphylococci are the most common bacteria found in cultures from the deep portions of hidradenitis suppurativa lesions, as obtained by carbon dioxide laser surgery.
Lapins J, Jarstrand C, Emtestam L (1999)
Br J Dermatol 140:9095

What the study by Lapins et al of aspirated pus finds is NOT that half of these deep samples show no bacterial presence, what it actually found is that BACTERIA WERE FOUND FROM DEEP LEVELS IN ALL BUT 3 OF 22 SAMPLES....

Coagulase-negative staphylococci are the most common bacteria found in cultures from the deep portions of hidradenitis suppurativa lesions, as obtained by carbon dioxide laser surgery.
Lapins J, Jarstrand C, Emtestam L.
Br J Dermatol. 1999 Jan;140(1):90-5.
Abstract
...Aerobic and anaerobic cultures from superficial and deep levels were taken during surgery. The regions treated were axillary in eight and perineal in 17 cases. Bacterial cultures were positive for one or more specimens from at least one level in all cases and from deep levels in all but three cases. Sixteen different species or sub-species were found. Staphylococcus aureus and coagulase-negative staphylococci (CNS) were the species most frequently found. Peptostreptococcus species and Propionibacterium acnes were not uncommon. S. aureus was detected in a total of 14 cases, six of which were from the deep levels. S. aureus was the sole bacterium isolated in two deep cultures. CNS were found in 21 patients and 16 of these isolates were from the deep levels. In nine of the 16 deep samples CNS were the only bacteria detected. These findings motivate a re-evaluation of the significance of bacteria in the progress of HS and in particular they suggest that CNS are true pathogens...
PMID: 10215774 [PubMed - indexed for MEDLINE]

THAT'S 13.5% NOT 50%... is that not correct?

And by the way, van der Zee doesn't seem to have noticed this article asserting that CNS Staph infections are troublemakers, being seemingly amazed at the thought of them causing the abscesses they are found in.

At least, the idea that our troubles come from commensal species of bacteria that are already everywhere provides that we probably don't need to worry about others catching HS from us, although given the laundry lists of bacteria that have been isolated from HS, I DO worry about contracting additional infections, which I seem to be good at.

And if one of these studies only used surface specimens from lesions as van der Zee states and it WASN'T Lapins et al?

It would be Jemec's study that only shows COMMENSAL, SKIN-SURFACE flora in only 50% of surface samples when they should probably be finding ordinary skin flora in up to 100% of samples, which could cast considerable doubt on the veracity of Jemec's study.

Unfortunately, I'm having trouble finding a free full text of Jemec's study
but if I can at least take that much of what van der Zee has to say seriously...?

It's just like those "sterile" swab results I've gotten - there's no way the swab has no bacteria on it - after being taken from the skin surface in my crack, it should offer at least a few commensal skin flora to culture, casting plenty of doubts on whether these results were worth wasting a swab. I have no idea what went wrong in Jemec's study but it certainly sounds like something did to judge by all this.

One other thing I could mention is that there are still bacteria which are "unculturable" and can't be grown in a dish from specimens (at least not until someone figures out what to feed them, all bacteria are "unculturable" until that happens obviously) and causal browsing of literature suggests there's good likelihood that these kind of organisms can come from the order of Bacteriodales that frequent isolates from HS like Bacteroides and Prevotella belong to, and they could be very similar in behavior and antibiotic response to the usually encountered types for all anyone knows.

Naturally if they can't get it to grow in a dish so they can try out different antibiotics to see what kills it instead of wasting antibiotics that aren't going to work, this poses a challenge, but nothing I've seen so far suggests that these elusive microbes could be at work in any more than about 10-15% of HS cases.

HS without bacteria? Is there such at thing? According to whom exactly?

As always my best advice to others with HS would be

1. Help your doctor to not underestimate the possible role of bacteria in causing your HS symptoms, and don't let them confuse an incurable disease with a treatable infection if you can possibly help it.

2. Encourage your doctor to be aware how common that problem-causing bacteria like Staphylococcus, Streptococcus and Bacteroides can be in HS, to do bacterial cultures, and if at all possible, to do susceptibility testing on cultures. The more stubborn someone's HS is, the more stubborn a bug they may have, the longer they've had it and the more antibiotics have failed them, the more likely it may become that they have something that could require these measures to find an antibiotic to successfully involve an infection.

I have an upcoming appointment where I intend to practice what I'm preaching here and see how it goes. It will be a new thing to get my doctor interested in my bacteriology outside of emergencies for once.

I could be wrong about all this stuff of course... but I do try not to be, because I hate this disease, I've had doctors threaten to saw me clean in half over this or obvious complications of it, the way it puts out a constant welcome mat for some of the scarier bacteria.

I know everyone else hates it too, I really wish I could come up with a "Treating HS for Dummies" for us all, but I wouldn't begin to know what advice to give someone without knowing their bacteriology, and if your doctor had that, they might not need some goofy patient like me to go and try to make it into a no-brainer for them.