Palmar skin is a different material
The skin on the palms and the palmar surfaces of the fingers is not a thicker version of the skin on your forearm. It is structurally different: a much thicker stratum corneum, a very high density of sweat glands, no hair follicles and effectively no sebaceous glands.
That combination is excellent for grip and abrasion resistance and poor for everything discussed in this publication. No sebaceous glands means no surface lipid film arriving from below to replace what is washed off. A thick corneum means that when the layer dries and stiffens, it does not flake away gracefully; it splits. A fissure in thick palmar skin can be deep, painful and slow, and it is a route through the barrier in a way that flaking is not.
The dorsal skin, the back of the hand, is a different problem again: thin, poorly padded, constantly exposed to wind and water, and stretched every time you make a fist. Most winter hand complaints in cold water sport are a combination of dorsal roughness and palmar or finger fissures.
The circulation is switched off exactly when you need it
In cold conditions the body reduces blood flow to the skin, and it does so most aggressively at the extremities, because that is how it defends core temperature. Hands and feet are first to go.
Reduced surface blood flow means reduced delivery of the substrates the epidermis needs to manufacture new cells and new lipid. So the site with the highest structural demand for repair is the one receiving the least support, for the duration of every session and for a while afterwards.
It also means hands stay cold long after you are otherwise warm, and cold skin is stiff skin, which brings us back to cracking.
Hands are washed more than anything else
Whatever your sport, your hands are also the part of you that meets soap. Domestic washing up, cooking, the bathroom, work hygiene, cleaning kit, filling a car. On a day when you shower once, you may wash your hands twelve times.
Each of those is a lipid removal event and a pH event, applied to skin with no sebaceous supply of its own. That is why occupational hand dermatitis is common in wet work occupations and why the Health and Safety Executive treats it as a preventable workplace issue with employer duties attached. If your hands are bad and your job requires frequent washing, that is not a personal failing and there may be occupational controls available to you.
The loop that keeps it open
The single most important thing about hand skin is that it is used. A split on a knuckle is subjected to a bending load every time the hand closes. A split on a fingertip is loaded every time you pick something up.
A fissure heals by the epidermis growing across the gap. Every time the gap is pulled open, that bridging is interrupted. This is the loop that turns a small winter crack into something that lasts until March.
Breaking the loop is mostly mechanical. Reduce the number of times the split is opened, keep the surrounding layer flexible so it does not tear further, and give the skin uninterrupted hours to bridge, which usually means overnight.
| Back of the hand | Palm and finger pads | |
|---|---|---|
| Corneum thickness | Thin | Very thick |
| Sebaceous supply | Some, via follicles | Effectively none |
| Main exposure | Wind, cold air, water, sun | Water, detergent, grip and abrasion |
| How it fails | Roughness, then fine cracks over the knuckles | Deep painful fissures, often at the finger pads and edges |
| What helps most | Cover against moving air, and an overnight layer | Fewer washes, warmth, and mechanical protection of splits |
Ordering framework written by this publication from general skin physiology. It is not a measurement, it is not taken from any study, and no number in it is a reading.
What actually helps
The controls that work on hands are the dullest in this publication.
Reduce the number of wash events. Rinse rather than wash where the task allows it. Where it does not, that is an occupational matter rather than a personal one.
Dry properly and gently, particularly between the fingers. Skin left wet in cold air evaporates, cools and stiffens. Skin rubbed dry with a rough towel loses cells.
Apply generously and, above all, at night. Nights are the only period when hands are not being used, washed or exposed. One thorough application before bed does more than four during a working day, because the other four are removed within the hour.
Cover the hands when the cold exposure is not the point. Gloves between sessions, in the car park, on the walk back. Warm hands are flexible hands and flexible skin does not split.
Deal with a fissure as a mechanical problem. Keeping the edges together and protected is the mechanism. How you do that is a practical question and, if the crack is deep, painful or not closing, it is a pharmacist's question rather than ours.
When hands stop being our subject
We are describing dry, cold, mechanically loaded skin in healthy people. Hands are also where several conditions we will not discuss present, and where the boundary between environmental dryness and something requiring assessment is genuinely hard to see from a website.
If hand skin is weeping, crusting, blistering, spreading beyond the exposed areas, itching enough to disturb sleep, or is not improving over a fortnight of genuinely reduced load, that is a pharmacist or a GP. If it is related to your work, say so when you go, because occupational causes change what happens next.