Why your shins are the driest part of you (and what actually helps)

Ask someone where their skin is driest and they'll usually say hands. Ask again in late August, after a month of heaters and long hot showers, and they'll roll up a trouser leg instead.

Shins. It's nearly always shins.

By this point in a Victorian winter they're often the worst skin on the body. Tight, chalky, faintly scaly, with scratch marks from three in the morning. If that's you, it isn't a sign you've let yourself go. Your shins were dealt a poor hand to begin with.

Your lower legs were short on oil from the start

Sebaceous glands, the tiny factories that make your skin's own oil, aren't spread evenly over the body. They cluster thickly on the face, scalp, chest and upper back. On the shins they're sparse. The skin down there is thinner too, sitting close to bone with less blood flow than almost anywhere else on you.

Then age does what age does. Oil and sweat output both taper off from the mid-forties and the decline gets steeper after sixty. Skin specialists have a name for the winter version of this, asteatotic eczema, and it shows up on the shins more than any other site. If your lower legs have started to look like the bottom of a dried-out dam, cracked into little plates, that's worth mentioning to your GP rather than solving with a new moisturiser. For most of us it never gets that far. It just itches, it gets worse every August, and we quietly file it under getting older.

The shower is doing more of this than the weather is

Here's the part that catches people out. Healthy skin sits at roughly pH 4.7 to 5.5, mildly acidic, which is how the enzymes that build your barrier lipids like it. Most supermarket body washes and commercial bars land up around pH 9 or 10. Wash in that daily and you swell the surface, upset the machinery underneath, and keep losing water for hours afterwards.

Then there are the surfactants. Sodium lauryl sulfate and its relatives are very good at lifting oil off a surface, and they can't tell the difference between the oil you picked up in the shed and the oil your skin made on purpose. On a shin that barely makes any to start with, that's a rough deal. Water temperature finishes the job. A hot shower in August feels magnificent for four minutes and charges you for it all day.

What a tallow bar does differently

Two things, really.

The first is superfat. We deliberately leave a portion of the fat unsaponified, so it never becomes soap at all. It stays in the bar as free oil and gets left behind on your skin as you rinse. Our bars for dry and mature skin run at 6 per cent, which is generous by commercial standards.

The second is what that leftover fat happens to be. Grass-fed beef tallow is roughly 30 to 45 per cent oleic acid, 20 to 30 per cent palmitic and 15 to 30 per cent stearic. Human sebum runs about 30 per cent oleic and 25 per cent palmitic. Not a perfect match, but close enough that tallow sits on skin easily, without the heavy film some plant butters leave. The saturated portion forms a light seal that slows water escaping, which a shin that no longer makes its own oil has to borrow from somewhere.

We'll be straight with you: nobody has run a proper clinical trial on tallow for skin. What exists is a couple of centuries of ordinary use, a fatty acid profile that lines up sensibly, and a lot of customers who write to say their legs stopped itching.

The two minutes after the shower matter most

If you change one thing this week, change this. Step out, pat down until you're damp rather than dripping, and put something occlusive on your legs while the skin is still holding water. You aren't adding moisture. You're keeping what's already in there from evaporating off. Leave it ten minutes and the moment has passed.

Two other habits worth adopting for the rest of winter: turn the shower down a notch, and leave the loofah off your shins, because friction on cracked skin only feeds the itch.

What we'd reach for

For the wash itself, the Gentle Soothing Soap Bar is the one we point dry-legged customers to first. Six per cent superfat, fragrance-free, nothing in it for reactive skin to argue with. Just Tallow 6% is the plainer version of the same idea, and if you want a little scent in the bathroom, Just Tallow in Lavender uses the same base.

For the two minutes afterwards, the Whipped Tallow Coconut Body Butter in Roman Chamomile is light enough to spread over a whole leg without dragging, and it stays put under trousers. If the night-time itch is the main event, keep a tin of Itch Relief Whipped Tallow Cream on the bedside table. The Tallow Calamine and Oat bar suits scratchy skin too.

Spring is a few weeks off and shins do recover once the heaters go quiet. Whether you get there comfortably comes down mostly to what you wash with and what you do straight after. Everything we make is rendered, cooked and cut here at Fulham Homestead in Victoria. Have a look through the range if your legs have had a hard winter of it.