For parents, the cycle of coughs and sniffles that plague young children can seem never-ending.

But simple saline nasal drops can reduce the duration of the common cold in youngsters by two days – and reduce onward transmission to other family members — according to a study.

Saline drops, which are available over-the-counter in the UK for as little as £1.30, consist of a simple mix of salt and water.

Researchers had noted that salt-water solutions are often used by people in South Asia — either in the nose or through gargling — to treat a cold and wanted to explore if this benefit could be replicated in a large study.

Professor Steve Cunningham, one of the study authors from the University of Edinburgh, said: 'Children have up to 10 to 12 upper respiratory tract infections, what we refer to as colds, per year, which have a big impact on them and their families.

'There are medicines to improve symptoms, such as paracetamol and ibuprofen, but no treatments that can make a cold get better quicker.'

The team recruited 407 children aged up to six years to a study where they were given either saline nasal drops or usual care when they developed a cold.

Overall, 301 children developed a cold — for 150 of these, their parents were given sea salt and taught to make and apply salt-water nose drops to the children's noses.

They were instructed to give three drops per nostril a minimum of four times per day, until they had recovered.

The other 151 children had usual cold care, such as other medicine.

'We found that children using salt-water nose drops had cold symptoms for an average of six days where those with usual care had symptoms for eight days,' Professor Cunningham said.

'The children receiving salt water nose drops also needed fewer medicines during their illness.

'Salt is made up of sodium and chloride. Chloride is used by the cells lining the nose and windpipes to produce hypochlorous acid within cells, which they use to defend against virus infection.

'By giving extra chloride this helps the cells produce more hypochlorous acid, which helps suppress viral replication, reducing the length of the virus infection, and therefore the duration of symptoms.'

When children got salt-water nose drops, fewer households reported family members catching a cold — 46 per cent compared to 61 per cent whose children received usual care.

Two-fifths of parents said the nose drops helped their child get better quickly, and the same amount said they would use them in the future.

Professor Cunningham added: 'Reducing the duration of colds in children means that fewer people in their house also get a cold, with clear implications for how quickly a household feels better and can return to their usual activities like school and work etc.

'Our study also showed that parents can safely make and administer nose drops to their children and therefore have some control over the common cold affecting their children.'

Commenting on the study Professor Alexander Möeller, from the University Children's Hospital Zurich, said: 'This is an important study that is the first of its kind to investigate the impact of salty nose drops in children with colds.

'Although most colds usually don't turn into anything serious, we all know how miserable they can be, especially for young children and their families.

'This extremely cheap and simple intervention has the potential to be applied globally; providing parents with a safe and effective way to limit the impact of colds in their children and family would represent a significant reduction in health and economic burden of this most common condition.'

The findings were presented at the European Respiratory Society Congress in Vienna, Austria.

Dr Andy Whittamore, Clinical Lead at Asthma + Lung UK, said: 'Shortening the time a child is poorly with a cold, with such an easily accessible solution such as salt-water nasal drops, will be a relief to parents and carers.

'The saline drops can even be made at home, are very safe for children and are easy to administer.

'Although colds are commonplace for children and rarely dangerous, in a recent survey we found around 3 in 4 people found colds and flu made their lung condition symptoms worse.

'Therefore, reducing the time someone is ill and contagious will help stop the spread of these respiratory infections.'