The Foot: Ward off blisters and warts

[Guest guest]

SPECIAL FITNESS ISSUE: THE FOOT

Ward off blisters and warts ...

Skin and nails may be resilient but they're also vulnerable to

fungus, friction and damage.

By Regina Nuzzo, Special to The Times

http://www.latimes.com/features/health/la-he-

surface1jan01,1,2081266.story?coll=la-headlines-health

Danger lurks: Public showers are hot spots for fungi that can cause

athlete's foot.

Skin and nails of the feet just don't get any respect. When

researchers talk foot science, they lavish attention on bones,

muscles, tendons and ligaments.

And when athletes trade stories in the locker room, they'll recount

the finer points of a plantar fasciitis episode — but are far less

likely to breathe a word about a wicked case of warts or toenail-

crumbling fungus.

Embarrassment: That's forgivable. Taking the humble foot wrapping

for granted: That would be nothing short of foolish.

Layers of resilient skin offer the first line of defense against

infection-causing microscopic nasties, and thick nail armor protects

toes' most vulnerable parts from bashing and bruising.

Well-exercised feet endure more abuse than the typical couch-potato

foot, meaning that trauma, fungi and viruses are more likely to

present problems. Ignore them and you run the risk of their getting

painfully out of control and keeping you on the sidelines.

Luckily, prevention and treatment for most athletic skin ailments is

simple. And scientists are steadily finding new solutions, using

tools such as sock-testing robotic feet and duct-tape home remedies.

Here's a closer look at the top five surface problems of feet.

Blisters

Cause: " Pure physics, " says Dr. B. , director of the

sports dermatology clinic at University of Cincinnati and author of

a textbook on the subject. Meaning: they're all about friction.

A new shoe that slips and rubs a bit on your heel may feel fine at

the store, but after 1,700 steps — a runner's typical mile — it can

peel away outer skin from the layers beneath. When that happens,

fluid rushes into the gap from surrounding tissue, and there's your

blister — painful, and a nice breeding ground for bacteria too.

Treatment: Don't rip off the skin flap. ( " There's no Band-Aid as

good as your own skin, " says.) Soak in warm Epsom salts. Big

blisters can also be sanitized, lanced with a sterilized needle and

drained, which speeds reabsorption of loose skin and helps keep

infection at bay.

Prevention: Also a matter of physics. Get shoes that fit well, says

Dr. Carolyn McAloon, a podiatrist in private practice in Castro

Valley, Calif. For super-sweaty feet, try rolling antiperspirant

along your soles. And for known hotspots, dab friction-reducing

petroleum jelly or a personal lubricant such as Astroglide, McAloon

adds.

Change socks often, because sweat actually increases frictional drag

on the skin. But watch what you're buying.

Recently, biological engineering students at the University of

Missouri-Columbia tested 10 brands of athletic socks in the lab

using a specially built device: a plastic foot to hold socks against

a simulated shoe, a motor to create a slow-motion stepping action,

and a humidity chamber to provide a realistic sweaty-foot

environment.

All-cotton socks were the worst, the students found, because

friction increased as soon as they cranked up the moisture. Price

tag wasn't a factor, however: Although an improvement over cotton,

expensive nylon blends were no better than bargain brands.

Athlete's foot

Cause: Mold-like fungi eat protein in the upper layer of your skin,

then leave their digested remains — a dense, moist, smelly mess — to

sit around on your foot, interlaced with still-healthy cells.

You can pick up the fungus from clothing, locker rooms, pool decks

and showers. But only in warm, moist conditions will it really

thrive — and odds are good you're cheerfully providing that. " A hot,

sweaty foot in an athletic shoe is a perfect environment, " says Dr.

Cordoro, a dermatology professor at University of Virginia.

Athletes are also more at risk than less active folks, she says,

because tiny, unnoticeable cuts and abrasions acquired during sports

activity are convenient " ports of entry " for the fungus to burrow

into, then spread.

Burning and itchiness aren't always the biggest problems,

though. " Think of the skin as the wall and the fungus as a vine, "

says. Fungi creep between layers of skin and destroy them from

within, giving harmful bacteria — such as Pseudomonas or

Staphylococci — a chance to invade. Healthy immune systems usually

can fight them off, but diabetics and other immunocompromised folks

are at risk for more serious infections.

Danger lurks: Public showers are hot spots for fungi that can cause

athlete's foot.

Treatment: Over-the-counter antifungal creams and powders, or a

short course of prescription oral medicine, usually wipe out

infections easily. Easier-to-use innovations are also under

development: A new topical formulation of terbinafine (the

antifungal in Lamisil) will form a thin film over the foot and

slowly release medication. In a recent European trial, a single

application cured athlete's foot in 63% of patients, compared with

17% in the placebo. For particularly thick athlete's foot, doctors

sometimes try creams with urea — a major component of urine — to

soften skin and let topical treatments penetrate better. But wives'

tales notwithstanding, one's own urine is unlikely to do the trick,

says. For one thing, most creams are 40% urea concentration,

compared with less than 20% for urine.

Prevention: Never go barefoot at the gym, McAloon says. Keep feet

dry and cool with antifungal sprays and powders. And be careful when

you're dressing: If you pull on tight underwear over bare feet, you

might drag the fungus straight up to your groin — another warm,

moist environment — where it can develop into jock itch.

Toenail fungus

Cause: The longer you have fungi sitting around on your feet, the

more likely they will wander around and start feeding on your

toenails too. " Once fungus infects the nail, it's a completely

different playing field, " says. Whereas athlete's foot sits on

the skin's top layers, toenail infections go deep through the nail,

where topical treatments can't easily reach.

Hungry fungi metabolize protein in the nail plates, tinting them

yellow or brown and littering foul-smelling debris beneath the tip.

Over time, nail layers start to split and grow thick and crumbly.

Athletes are extra susceptible, McAloon says, because toenails

bruised and banged about from sports can make it easier for the

fungus to settle in.

Treatment: Oral antifungals taken daily for three months are

effective against toenail infections, but the long treatment —

compared with that for athlete's foot, which is often cured in two

to four weeks — also brings the risk of liver complications such as

hepatitis, Cordoro says. New, deep-reaching topical treatments are

being tested: Small molecules in one lacquer, right now known only

as AN2690, slip more easily through tough nail layers and deliver

fungicide to the skin beneath. Clinical trials are ongoing;

preliminary results found that about half of nails treated daily for

six months ended up growing fungus-free.

Prevention: Treat athlete's foot early to keep the fungus from

spreading to nails. Make your toes dry, inhospitable places for

fungus to live. And consider nagging your housemates about hygiene:

A recent study of 57 households by researchers at University

Hospitals of Cleveland found that foot fungi were passed along

person-to-person about half the time — and even more often if a

member's infected toenails had already started to discolor.

Runner's toe

Cause: Not every ugly toenail is teeming with fungus. Equally common

is " tennis toe " or " runner's toe, " where physical trauma, not

infection, is to blame.

The toenail's purpose is to protect plush, vulnerable toe tips from

damage. But repeated banging against the front of the shoe —

especially in stop-and-go sports like tennis and soccer — can burst

small blood vessels under nails, says Dr. Schoene, a sports

medicine podiatrist in Chicago. When that happens, blood blisters

bubble up and lend toenails a pearly black tinge — often until the

painful pressure splits off nails from the skin entirely. (They

usually grow back, but with repeated injury, toenails can sometimes

grow in thick and deformed.)

Treatment: To ease the pressure and let blood escape — which might

save the toenail — doctors sometimes burn a small hole in the top of

the nail with a hot, sterilized needle, a process called

trephination.

But it's tricky to get deep enough into the nail without going too

far and searing skin. So researchers have developed a new " micro-

cutting " power tool called the PathFormer. As sharp tips drill

downward, sensors monitor changes in the water composition of nail

layers. As soon as the tool detects moist skin ahead, the blades

retract, sparing the tender nail bed.

In a pilot study of 14 people published in June in the journal

Dermatologic Surgery, patients reported minimal pain and pressure —

with no bleeding or skin punctures.

Prevention: The best prevention for runner's toe is keeping the

nails trimmed neat and short, Schoene says, and wearing good shoes

with a proper fit.

Plantar warts

Cause: Human papilloma viruses (different strains than those causing

cervical cancer) infect and hijack skin cells, forcing them to grow

extra protective flesh to encircle the viruses' DNA. Black spots dot

the wart's surface when fast-growing blood vessels get clogged up.

Though harmless, plantar warts still hurt because as these tough

nodules develop on the bottom of weight-bearing soles or heels, they

start growing up back inside your body instead of growing outward as

they do on other parts of your skin. " It's like having a pebble in

your shoe that feels like a boulder, " says.

Treatment: Remove the extra wart flesh, which will encourage your

body's immune system to dispatch the virus on its own. Doctors often

use corrosive solutions such as salicylic acid and then cut away the

wart with a scalpel or freeze it off with liquid nitrogen.

Do-it-yourselfers have other options: a therapy of duct tape, pumice

stone and patience. In 2002, researchers at the Cincinnati

Children's Hospital Medical Center published results of a study of

51 kids with warts. Doctors first covered the wart in duct tape for

six days, then removed the tape, soaked the area in water and pared

it down with an emery board or pumice stone. The next morning, new

duct tape was applied and the whole process repeated.

After two months, 85% of the warts in the duct-tape group had

disappeared, compared with 60% in another group receiving liquid-

nitrogen treatment.

But we may not have the last word on duct tape yet: In a study

published in November, researchers tried the approach and found it

to be no better at curing warts than a placebo. The researchers

noted, however, that they used a different, less-sticky type of duct

tape than the traditional, silver kind.

Prevention: Viruses are passed along from skin-to-skin and floor-to-

barefoot contact, just as with fungus, so keep your flip-flops on —

and just say no to footsies with warty feet.