PM David Cameron has a infected ear
Prime Minister David Cameron was treated for swimmer's ear while on vacation in PortugalPeter Macdiarmid/Getty Images

David Cameron had to seek medical treatment for a case of swimmer's ear summer holiday in Portugal.

Otitis – also known as "swimmer's ear" – a painful condition that causes inflammation, redness and swelling of the external ear canal, according to the NHS.

It's called "swimmer's ear" because it is often the result of repeated exposure to water, which makes the ear canal more vulnerable to inflammation.

"He was here for around 20 minutes, half an hour. During that time, he was seen by a nurse from our centre and then a doctor," Dr Manuel Veloso, head of a local medical centre told The Times.

Downing Street say the prime minister picked up otitis while surfing in the Algarve, where he is staying with his family.

He has now recovered from the common condition and is enjoying his second holiday of the summer with his wife, Samantha, and their three children.

It is not the first time Cameron has seen an injury when on a seaside holiday. He was stung by a jellyfish while swimming in the sea in Lanzarote last Easter.

Sources told the Independent that the prime minister will "be gone for most of August", insisting he deserved a break following his surprise general election victory and 100 days of Tory majority leadership.

In 2012, Cameron said he was a "great believer" in politicians taking breaks. "If you don't think politicians ought to have holidays I think you need to have a serious think," he said the Independent 2012.

Cameron has been on at least 14 holidays since entering Downing Street, on top of three Christmas and New Year breaks. Among his favourite destinations are Tuscany, the Algarve, Ibiza, Andalusia, Jura, Grenada, Cornwall and Lanzarote.

But the Prime Minister is expected to return to Downing Street for the "odd day" and will still perform duties such as attending today's VJ Day commemoration in London.