Gaius Julius Caesar Octavianus was the nephew and grandson of Julius Caesar. Born in Rome in 63 BCE, he died in Naples in 14 CE. His age of 76 years at death was advanced for the time.

According to the historians Pliny the Younger (61–112 CE) and Gaius Suetonius (70–126 CE), the emperor suffered from a chronic pruriginous skin disease.1

Although we lack clinical images confirming his condition,2 it is thought that he would probably have met the Hanifin–Rajka diagnostic criteria for atopic dermatitis4 based on clinical details and the fact that he might also havehad asthma.3

We have no information about therapies used to control his symptoms, but it is likely that baths were among the measures prescribed.5

A physician, writer, and Jacobin during the French Revolution, Marat was born in Boudry in 1743 and died in Paris in 1793.

Marat had a crusting, foul-smelling, and severely pruriginous skin disease that he attempted to treat by immersing himself in long, hot baths.

In fact, it was while Marat was in his bath that he was murdered by Charlotte Corday (1768–1793), a member of the rival Girondin political faction during the Revolution. The place of assassination suggests that Marat’s skin disease might have played a hand in changing the course of history.6

There is no consensus on Marat’s diagnosis.7 Speculations have included common contemporary diseases, such as syphilis, which did not usually cause a pruriginous rash, or scabies — for which a treatment existed, something that a physician like Marat must have known. Other less common diseases that have been proposed include atopic, seborrheic, or herpetiform dermatitis. It is plausible that Marat had dermatitis herpetiformis. Besides being a severely pruriginous condition, this disease’s blisters contain a watery fluid that forms crusts. There was no specific treatment available in Marat’s day, as sulfa drugs (sulfonamide antibacterials) were not introduced until the 1930s.

Born in Dublin in 1845, Oscar Wilde died of meningoencephalitis in Paris in 1900. He was a writer known for solid argumentation and the witty, biting humor of his conversation. The Victorian morality of his time could not condone his homosexuality, for which he was sent to prison.

Wilde was said to break out in a severe pruriginous rash of erythematous macules on his face, shoulders and the upper third of his trunk.8 The rash appeared intermittently, and at first he associated it with eating mussels. However, he later ruled out that cause on finding that it disappeared after he received the blessing of Pope Leo XIII.9

Nater8 claimed that Wilde, a quintessential dandy who could not abide the physical changes that came with the passage of time, dyed his hair to appear younger. The skin symptoms reported would be compatible with contact dermatitis from hair dye containing p-phenylenediamine, the agent most often responsible for sensitivity reactions in this scenario.

The British prime minister Neville Chamberlain was born in 1869 and died in 1940.

On a trip to his family’s plantations in the Bahamas in 1891, Chamberlain noted in his diary that a rash had broken out on one of his legs. The future politician reported the presence of large blisters, some of which were probably hemorrhagic. Before the rash appeared, he had been sitting on the trunk of a local poisonwood tree, known by the names guao or chechen.

This tree, thought to be Metopium toxiferum, produces urushiol, a toxic substance that causes an irritative contact dermatitis—the likely final dermatologic diagnosis.10