Bitten by the bug: Skin infections

“I think you have cellulitis”. Usually if I say this to patients, they look horrified - so it’s swiftly followed by the explanation that this is nothing to do with cellulite, nor am I implying there is any cellulite present! Once the panic has dissipated, I go on to explain what it is - essentially, a bacterial infection of the skin, and the subcutaneous fat just below the skin.

Cellulitis is caused when there is break in the skin, which allows the bacteria to get underneath - this exposed tissue is perfect for them to multiply in and cause infection. The bacteria that usually cause cellulitis are present on everyone’s skin naturally, however, when they get underneath it where they don’t really belong, they can cause this problem.

We’ve all had cuts or bites at some point in our lives. It's sensible to wash any of these wounds with clean running water for a few minutes, or use some antiseptic on them if you can. Despite this, sometimes the skin and tissue surrounding the cut/bite can become swollen, and is tender and hot to touch - a good example of mild cellulitis. The redness often “blanches” - that is, when you press your finger on it, apply some pressure and then remove your finger, the skin is briefly whitened then returns to red after a second or two. The area of redness usually has a relatively clear rim or edge to it - and this can be a useful tool (something I’ll come back to later).

If it’s just a small area of redness (i.e. less than a centimetre or so) then your body may well deal with it naturally. However, if the area of redness is growing, becoming increasingly painful or warm, then the likelihood is that this may need treatment with antibiotics. As we know which bacteria are causing it (usually one of the staph. or strep. family) we know it responds well to certain antibiotics. I usually prescribe a course of at least 7 days, and sometimes up to 14 depending upon the severity and response.

It’s a good idea to take a biro or permanent pen and try and draw around that rim of redness. This way you get a really clear idea whether things are improving (which they should), but if the redness is still spreading you need to see your doctor again. Another simple measure is taking some ibuprofen to try and reduce any swelling, and if possible, elevating the part of your body that is affected (if it’s an arm or leg obviously!).

One important point to note is that if you have been bitten by an animal (this also applies to human bites, but not insects) then you need to ensure you are up to date with your tetanus immunity. If you’ve had a tetanus booster within the last 10 years you should have effective immunity. Tetanus is rare in the UK (there were only three cases in 2011), but it can affect deep tissue wounds that have become contaminated, and is easily preventable. Rabies is another possible complication of animal bites, but is all but eliminated in the UK. However, it is a consideration if you are going to certain countries abroad, and I'd recommend discussing possible vaccination prior to travel.

Cellulitis often affects the limbs but can affect any part of the body. There are certain parts of the body we treat differently. For instance, around the eye (periorbital cellulitis) is a rather delicate area, and needs urgent medical assessment and treatment with intravenous antibiotics. This is a condition which often affects young children, but can also affect the elderly.

If in doubt, get it checked out. This way if it’s nothing, you can relax, and if it’s cellulitis you can relax too as you’ll be getting the right treatment!

I can be reached on the number and email below, or alternatively Dr Morton's - The Medical Helpline is another great source of help