Skin and blister - little sister. I'm not entirely sure where the phrase comes from (Cockney rhyming slang, perhaps?), but like little sisters, blisters can be a real pain. They are fluid filled sacks with a thin layer of almost transparent skin covering them. Blisters plague many hillwalkers. They can turn a pleasant trek in the mountains into an agonising ordeal where every step feels like a step closer to the doors of Hell. They are caused by friction, repeated pressure to skin areas, or extremes in temperature, either hot or cold. Blisters can be filled with either a watery fluid or blood. If they are filled with pus, then they are not blisters, but abscesses, and these indicate an infection is present and medical treatment must be sought as quickly as possible.
Blisters can also be dangerous for people with diabetics, poor circulation or decreased feeling in their feet, those with compromised immune systems, and those with other serious diseases. If you fall into any of these categories, you are advised to see you doctor at the first sign of blister formation.
If you are healthy, then blisters can be treated with relative ease. The
priority is to keep the area of the blister clean, to prevent any risk of
infection. As a general rule blisters should not be broken, unless they are very
painful, or they are in an area where there is continued shoe pressure, which
will break the blister with continued walking. As long as the blister is left
intact, there is less chance of it becoming infected. At the end of the day, a
blister is the body's own way of cooling friction burns to the skin.
However, if you are undertaking a lengthy trek it may become necessary to burst the blister. Before you do this, make sure the blister and skin around it is clean. Do this with a sterile wipe (which you should find in your first aid kit), or use alcohol (if you're carrying a hipflask with whisky in it for a summit celebration).
The next step is to sterilize a clean needle, pin, or small scissors, by heating the tip for a few seconds with a flame from a match or cigarette lighter. If this is not possible, soak the needle in alcohol to cleanse it, although this will not sterilize it and there is a risk of infection.
Carefully prick the blister to make a small hole in it. Do not insert the needle deeply - just enough to go through the top covering of the blister. You do not want to go so deep that you go through the entire blister, and into the underlying tissue. Gently squeeze the fluid out of the blister. This should relieve the pressure and it should feel less painful. Do not cut away the skin covering the blister as leaving the top cover of the blister intact helps to prevent infection.
Apply antiseptic cream to the area of the blister and cover with gauze and tape. Avoid simply putting a plaster over the wound as it will not absorb blister fluid. Pad the area of foot up as much as possible to prevent further friction. Ideally, you want to keep all pressure off of the blister while it is healing but this is not always possible while out walking.
Like so many things in life, prevention is better than cure. In a bid to avoid blisters your boots must fit properly and be comfortable. The wrong boot size is the most common cause of blisters. Make sure the inside lining and innersole are not worn. Wear good quality hillwalking socks that fit properly. Ideally, you should wear two pairs of socks (a thinner sock or liner sock under a thick pair of hillwalking socks) and remember that holes in socks cause blisters. If you have bony protrusions, or sensitive skin areas, on your toes or feet, protect them with additional padding.
Recurring blister problems are usually due to abnormal foot structures or gait patterns. Flat feet, feet with very high arches, bunions, and pronation (a rolling out of the feet, so that when you walk you apply excessive force to the inner side of your feet), are all foot problems that can be successfully treated. A visit to the chiropodist will help here.
Finally, while we are on the subject of foot care, make sure you keep your toenails trimmed. Long or jagged nails can dig into neighbouring toes, causing considerable discomfort.