Follicular Flood Furphies
Brisbane is flooded again, although thankfully not as badly as in 2011. It is always worth a shout-out to the awesome work our emergency services to – particularly the volunteers in the State Emergency Service who get out and about to help out while the disasters are ongoing and without any payment or reward.
I had a brief exchange with one Brisbane volunteer here over the weekend and again today, in response to a similar tweet coming from St John’s Qld. After a quick bit of Googling and some Pubmed, my assessment is here and here – there is no direct evidence or guidelines (that I have been able to find) that recommend this.
So where has this helpful advice come from? And why is someone who’s job is preventing infection having a cranky about it?
Well, like many of these things, there is a seed of truth at the bottom of it all. In preventing surgical site infections, there are actually really quite a few studies (including a Cochrane review) of the impact of methods of hair removal on the risk of getting a surgical site infection if you’re having an operation. The bottom-line: we don’t really know, because the studies are small, the events are rare. The data is underpowered to find a difference between no hair removal and hair removal, but what they do say is that if you shave, your risk of infection is around twice that if you clip (relative risk: 2.09, 95% CI: 1.15-3.80). It is now standard surgical practice for hair to be clipped, not shaved.
Why this might increase your risk of surgical infection is unclear; microtrauma to the skin is a popular theory, but there are others – opening the pores to allow bacteria normally on the skin surface to gain entry into the hair follicles is another. The thing you have to remember is that surgery is a major insult to your skin. (After lathering it with antiseptic) it is cut, stretched, sometimes burnt and then stitched. It creates a cold, poorly blood-supplied bit of tissue that is open to the outside world into which the residual bacteria (which residual bacteria? These ones. Surgical prep is better than hand sanitizer, but your skin is not sterile) fall and can set up a wound infection.
This is not your leg in a gumboot full of Brisbane river water.
What we do know is that healthcare staff do see an increase in the number of skin and soft-tissue infections in the period immediately post flood. We certainly did in Brisbane in 2011. There is also a small increase in the number of unusual infections (things like Aeromonas – which likes living in fresh water but is normally a very rare cause of wound infections) but the vast majority of these are caused by Staphylococcus and Streptococcus – which are germs that are living on your skin right now.
Why do we see these infections after floods? I’d guess that there is a combination of factors, including cuts and abrasions from submerged debris. In the Queensland summer, I reckon tinea pedis is a major player – one of our tricks of the trade in infectious diseases is to cure a person with recurrent bacterial leg infections by looking between their toes and treating their tinea – causing splits which let the bacteria in – which no other doctor has thought to look for. The other infection that people have mentioned is “that foot spa thing” – you’re probably thinking of Mycobacterium fortuitum – which lives in fresh water and likes warm places – and isn’t killed by whatever that awful radioactive blue antiseptic they put in those foot spas. It’s not much of an issue in floods, but the hair pulling and then soaking your feet in a warm pool of contaminated water is a risk for infection. (Disclaimer for foot spa attendees: it’s quite rare, so don’t stress).
So perhaps shaving your legs could have a minor impact on the risk of infection, and surely if we can do anything to prevent infection we should? Well, I don’t think it’s always the case.
I think that emphasising the wrong message is harmful. People (unfortunately) have limited capacity to remember public health messages. I think it’s far more important to emphasise the importance of hand washing after grubbing around in the mud than to focus on the shaving message. It’s a much more bang-for-your-buck intervention.
In a way, it’s like telling tourists to North Queensland that they should watch out for red-backs under the toilet seat rather than not swimming where crocodiles or irukanji might be lurking – or for that matter, not encouraging them to cover up from the sun.
Most of these skin and soft tissue infections will be mild and self-limiting.
The important messages are to:
- keep any wounds you do have covered up
- wash your hands
- if you do develop an infection, see your doctor
- mention that you’ve been working in the floods
and don’t stress out if you’ve shaved your legs. It’s probably not going to make that much difference. Even less so for your face or armpits. The Queensland Health public health communique that will be sent to doctors statewide shortly doesn’t mention a damn thing about shaving, and neither does any flood-response guideline I’ve been able to find on the internet, so stop putting the fear of pestilence into shavers everywhere.
But wash your hands!