2,500 years from a new nose cut from the cheek in ancient India to lab-grown skin, touch sensors and a fairer scale for every skin tone.
Healers in ancient India already knew that a living flap of skin could be moved and made to heal in a new place. Microscopes later showed that skin is built in layers, packed with tiny sensors, pigment cells and sweat glands. In the last hundred years people learned how skin uses sunlight to make vitamin D, how to grow new skin in a lab to save burn patients, and why human skin comes in so many colours.
Oldest known written account of rebuilding a nose with a skin flap
Sushruta Samhita, India
1665
Skin layers described under a microscope
Marcello Malpighi, Italy
22 October 1814
First plastic surgery operation in Britain
Joseph Carpue, England, using the Indian method
1869
Pinch skin grafts
Jaques-Louis Reverdin, Paris
1946
Modern sunscreen (attributed)
Franz Greiter, Gletscher Crème
1975
Human skin cells grown in the lab
James Rheinwald and Howard Green, USA
1978 (some sources say 1972)
First skin bank in India
Manohar H. Keswani, Mumbai
27 May 1992
First national UV index forecast
Environment Canada
c. 600 BCE by tradition; the text was likely written and expanded over many centuriesHealers and new noses
600 BCE – 1600
Healers and new noses
Indian surgeons describe skin in layers and move living flaps of it to rebuild noses. Greek and Roman doctors use the skin of the hand to feel a patient's heat.
600 BCE
c. 600 BCE by tradition; the text was likely written and expanded over many centuries
Seven layers of skin
Sushruta and later editors (attributed)Ancient India (Varanasi by tradition)
The Sushruta Samhita, a great Sanskrit book of surgery, describes the skin (tvak) as seven layers, from a thin outer one that shows the body's colour to a deep one that holds the flesh. Scholars disagree on its age: tradition says about 600 BCE, but many think it was begun in the last centuries BCE and finished centuries later.
Why it mattered. It is one of the oldest known attempts to picture skin as a stack of layers, an idea microscopes would confirm much later.
c. 600 BCE by tradition; possibly several centuries later
A new nose from the cheek
Sushruta (attributed)Ancient India
The Sushruta Samhita explains how to rebuild a nose that has been cut off, using a flap of skin from the cheek. The flap stays joined at one end, so it keeps its blood supply while it heals in its new place. It is the first known written record of this kind of operation.
Why it mattered. A living flap of skin that can move and heal elsewhere is the idea at the heart of plastic surgery.
Galen, a Greek doctor working in Rome, taught that every body is a mixture of hot, cold, wet and dry. In his book Mixtures he trained doctors to judge that mixture partly by touch, using their own skin as the measuring tool. His ideas guided medicine for well over a thousand years.
Why it mattered. It treated skin as a sensing instrument, long before anyone knew how skin senses anything.
The microscope reveals the layers under the surface. A report from India teaches Europe plastic surgery, and skin diseases get proper names.
1665
The microscope finds the layers
Marcello MalpighiItaly
Marcello Malpighi looked at the tongue and skin through an early microscope. In a 1665 letter on the outer organ of touch (De externo tactus organo) he described tiny bumps called papillae and a soft layer under the tough outer skin. The living bottom part of the epidermis is still sometimes called the Malpighian layer.
Why it mattered. It showed that skin is built in layers, each with its own job.
Cowasjee and an Indian surgeon; letter signed only “B.L.”Near Pune, India; printed in London
The Gentleman's Magazine in London printed a letter about Cowasjee, a bullock driver for the British army whose nose had been cut off after he was captured by Tipu Sultan's forces. Near Pune, an Indian surgeon had given him a new nose using a flap of skin from his forehead. The method was thought to have been practised in India for centuries.
Why it mattered. This “Indian method” reached European surgeons and helped start modern plastic surgery.
Robert Willan sorted skin diseases by how they look, such as spots, blisters or scales, and gave each a clear name with coloured pictures. His book On Cutaneous Diseases came out in parts, and its first volume was completed in 1808. Many of his names are still used.
Why it mattered. Clear names let doctors everywhere agree on what they were seeing, the start of modern dermatology.
Inspired by the reports from India, surgeon Joseph Carpue rebuilt an army officer's nose with a flap of skin from the forehead. The operation took about 15 minutes, with no anaesthetic. In 1816 he published two successful cases, and the method spread across Europe.
Why it mattered. It was the first plastic surgery operation in Britain, and it came straight from Indian practice.
Scientists test how finely skin can feel and find the tiny sensors that do it. Surgeons learn that small pieces of skin can grow over a wound.
1834
One point or two?
Ernst Heinrich WeberLeipzig, Germany
Weber touched people's skin with the two tips of a compass and asked if they felt one point or two. On the fingertips and tongue, points a few millimetres apart felt separate, but on the back they had to be several centimetres apart. He published this in De Tactu (On Touch) in 1834.
Why it mattered. It showed that some patches of skin are packed with far more touch sensors than others.
Deep in the skin sit tiny capsules made of many layers, like an onion, wrapped around a nerve ending. Abraham Vater in Germany reported them in 1741, but they were forgotten until Filippo Pacini found them again in 1835. They respond to vibration and pressure.
Why it mattered. They were among the first touch sensors ever found in the skin.
Georg Meissner and Rudolf WagnerGöttingen, Germany
Working in Rudolf Wagner's lab, the young Georg Meissner found small oval bodies wrapped around nerve endings in the ridges of fingertip skin. The two published them together in 1852, then argued for years over who deserved the credit. Meissner corpuscles sense light touch and gentle flutter.
Why it mattered. It linked a feeling, light touch, to a structure you can see in the skin.
Paul Langerhans, a 21-year-old medical student, spotted branching cells in the epidermis. Because of their branches he thought they were part of the nervous system. They turned out to be immune cells that catch germs and show them to the body's defences.
Why it mattered. The skin is not just a wall: it has its own guards.
Jaques-Louis Reverdin, a Swiss surgeon training in Paris, placed tiny pinches of healthy skin onto a wound that would not heal. Each little island spread outwards until the wound closed over. These pinch grafts began the modern era of skin grafting.
Why it mattered. It proved that skin cells can spread and cover a wound, the idea behind every skin graft.
Friedrich Merkel gave the first full description of special cells at the base of the epidermis, each paired with a nerve ending. He called them Tastzellen, touch cells. Today Merkel cells are known to help us feel edges, shapes and textures.
Why it mattered. It added another type of sensor to the growing map of how skin feels.
The cells that make skin colour are found, sunlight on skin is shown to cure rickets, and sweat is measured as the body's cooling system.
1917
Where skin colour is made
Bruno BlochSwitzerland
Swiss dermatologist Bruno Bloch added a chemical called DOPA to thin slices of skin. Some cells in the bottom layer turned dark, showing they held the enzyme that makes the pigment melanin. These pigment-making cells are now called melanocytes.
Why it mattered. It pinned down the cells that give skin its colour and its shield against UV light.
Kurt Huldschinsky; Alfred Hess and Lester UngerBerlin, Germany; New York, USA
In Berlin, Kurt Huldschinsky shone an ultraviolet lamp on children with rickets, a disease that leaves bones soft and bent. X-rays showed their bones healing, even in an arm that was never lit. In 1921 Alfred Hess and Lester Unger in New York cured rickets by putting children in sunlight on a hospital roof.
Why it mattered. It revealed that skin makes something the whole body needs, later named vitamin D, when sunlight falls on it.
Japanese physiologist Yas Kuno spent his life measuring sweat, using a device that weighed the water leaving a patch of skin every few minutes. His 1934 book The Physiology of Human Perspiration was the first work on body temperature control from Japan. He showed there are two kinds of sweating: for heat, and for nerves.
Why it mattered. It explained how evaporating sweat lets skin cool the whole body.
Sunscreen and SPF arrive, burn care improves decade by decade, skin banks open, and new skin is grown in the lab from a few cells.
1946
1946 (SPF introduced in 1974)
Glacier cream and SPF
Franz GreiterAustria (named after Piz Buin, a peak in the Alps)
After a bad sunburn while climbing the mountain Piz Buin in 1938, chemistry student Franz Greiter set out to make a better sun cream. In 1946 he launched Gletscher Crème (glacier cream), often called the first modern sunscreen, with an estimated SPF of only about 2. In 1974 he introduced the sun protection factor, the SPF number on bottles today.
Why it mattered. It gave people a way to shield their skin from UV and a number to compare one cream with another.
At a British burns unit, Bull and Squire found a way to measure progress: the burn size, as a share of the body's skin, at which half of patients die. For people aged 15 to 44 it was about 43% of the skin. Tracking this number for decades showed how much better burn care became.
Why it mattered. It turned “are we getting better at treating burns?” into a question with a clear answer.
Stanley Cohen found a protein that made newborn mice open their eyes and grow teeth early. He named it epidermal growth factor, because it makes skin cells multiply. He shared the 1986 Nobel Prize with Rita Levi-Montalcini for the discovery of growth factors.
Why it mattered. It revealed one of the chemical messages that tell skin to renew itself and heal.
James Rheinwald and Howard GreenCambridge, Massachusetts, USA
James Rheinwald and Howard Green found how to grow human skin cells, called keratinocytes, in the lab on a layer of mouse “feeder” cells. A few cells from a small piece of skin could multiply into sheets of new epidermis. They published it in the journal Cell in 1975.
Why it mattered. For the first time, new skin could be made in large amounts from a tiny sample.
Manohar H. KeswaniBai Jerbai Wadia Hospital, Mumbai
Burns surgeon Manohar Keswani set up India's first skin bank in Mumbai, to store skin donated after death so it could cover burn wounds. He had already opened the country's first children's burns unit there in 1975. The bank struggled for money and public awareness, but skin banking has since spread to other Indian cities.
Why it mattered. Donated skin can act as a living bandage that helps save people with very large burns.
Howard Green's lab, with surgeons including Nicholas O'Connor and G. Gregory GallicoBoston, Massachusetts, USA
In 1983 two young brothers from Wyoming, Jamie and Glen Selby, were burned over more than 95% of their bodies. Howard Green's lab grew sheets of new skin from small patches of their unburned skin, and surgeons covered their wounds with it. Both boys survived, after cultured skin had first been tried on smaller burns in 1981.
Why it mattered. It showed that skin grown in a lab could save people who had almost none of their own left.
Robert Friedman, Darrell Rigel and Alfred KopfNew York, USA
Three doctors at New York University gave the public a simple checklist for spotting melanoma, a dangerous skin cancer: Asymmetry, Border, Colour and Diameter. An E, for a mole that is Evolving or changing, was added later.
Why it mattered. Anyone could now check their own skin, and melanomas caught early are far easier to treat.
The burn size, as a share of the body's skin, at which half of patients aged 15 to 44 died (the LA50). Higher means better care. Reports from different UK and US hospitals, gathered in one table by Capek et al., 2018.
1949 1949, Bull and Squire (UK): 43% (Capek et al., J Am Coll Surg 2018, Table 1)
1954 1954, Bull and Fisher (UK): 46% (Capek et al., 2018, Table 1)
Science explains why skin colour varies, finds the molecules for heat, cold and touch, and builds tools that work fairly for every skin tone.
1975
1975 (six types by 1988)
Skin types for UV treatment
Thomas B. FitzpatrickBoston, Massachusetts, USA
Dermatologist Thomas Fitzpatrick made a scale of skin types based on how easily skin burns or tans in the sun. It was built to choose safe doses of UV light for a psoriasis treatment called PUVA, not to describe skin colour. The first version had four types for white skin, and types V and VI for brown and black skin were added later.
Why it mattered. It became the standard way to predict how skin reacts to sunlight, though it was never meant to cover every skin tone.
Environment Canada scientists; WHO and WMOToronto, Canada; Geneva, Switzerland
Canadian scientists created the UV index, and Canada began forecasting it with the weather on 27 May 1992. In 1994 the World Health Organization and World Meteorological Organization agreed one global version. In 2002 they published a guide with its colour scale and advice on protecting skin.
Why it mattered. It told everyone, every day, how quickly sunlight could burn their skin.
David Julius and teamSan Francisco, California, USA
David Julius and his team used capsaicin, the chemical that makes chillies hot, to find a sensor on nerve endings in the skin that also fires in painful heat. It is now called TRPV1. In 2002 his team and Ardem Patapoutian's found TRPM8, a sensor set off by cold and by menthol.
Why it mattered. It explained, molecule by molecule, how skin feels heat and cold.
Nina Jablonski and George ChaplinSan Francisco, California, USA
Anthropologist Nina Jablonski and geographer George Chaplin compared skin colour around the world with how much UV light people's ancestors lived under. Where UV is strong, dark skin protects folate, a vitamin needed for healthy babies. Where UV is weak, lighter skin lets in enough to make vitamin D.
Why it mattered. It explained human skin colour as a balance struck by evolution, not a ranking.
Colin Palmer, Irwin McLean and colleaguesDundee, Scotland
Researchers found that many people with eczema carry faulty copies of the gene for filaggrin, a protein that helps build the skin's tough outer barrier. With a weaker barrier, water escapes and irritants and germs get in more easily.
Why it mattered. It showed that the outer layer of skin is a working barrier, and that when it fails, disease can follow.
Ardem Patapoutian and teamLa Jolla, California, USA
Ardem Patapoutian's team tested gene after gene to find sensors that open when a cell is pressed, and found Piezo1 and Piezo2 in 2010. In 2014 they showed that Piezo2 is the main sensor for light touch in mouse skin. Patapoutian, born in Lebanon, shared the 2021 Nobel Prize with David Julius.
Why it mattered. It found the switch that turns a gentle press on the skin into a nerve signal.
Ellis Monk, with GoogleHarvard University and Google, USA
Harvard sociologist Ellis Monk designed a scale of 10 skin tones, and Google released it openly in May 2022. It is used to check whether cameras, search and computer vision work fairly for people of every skin tone. It covers deep skin tones better than the older Fitzpatrick scale.
Why it mattered. Tools built for everyone should be tested on everyone's skin.