CVS has been recognised for over 100 years, but we still know very little about the cause of the problem and there is still no recognised treatment.
CVS is characterised by recurrent, prolonged attacks of severe vomiting, nausea and lethargy, with no apparent cause. Vomiting persists at frequent intervals, 5-6 times per hour at the peak, for periods ranging from hours to10 days or more. It most commonly lasts for between 1 and 4 days. The episodes are self-limiting and tend to be similar to each other in symptoms and duration. The sufferer is generally in good health between episodes.
CVS is a syndrome, not a disease. When other causes have been excluded, what is left may be classified as CVS. This means that people with CVS may show a range of symptoms, one goal of the CVSA is to help develop better diagnostic criteria, so that sufferers are diagnosed more quickly and accurately than has been the case previously.
Who gets CVS?
The onset of CVS can occur from infancy to adulthood. It most commonly develops between the age of 3-7 years and it can persist from months to decades. It affects male and female equally. As the name suggests, cyclic activity is often a feature of this condition. About 50% of sufferers show a strong regular pattern of vomiting episodes. The episodes may occur as often as several times a month or as little as several times a year.
CVS sufferers are more likely than average to have a family history of migraine, and/or travel sickness, but the association is not dramatic, more a trend.
A number of studies have been performed to estimate how common CVS is. Studies from Australia and Scotland have suggested that about 2% of children may be affected.
What Triggers a vomiting episode?
For many with CVS there is nothing obvious that starts an attack, for others some specific "Triggers" can be identified which may initiate a CVS episode. One of the most common factor reported is illness, where mild infections such as colds, 'flu, viral infections, injury or pain and a range of other illnesses may start an episode.
Less commonly, food sensitivities, anaesthetics, cold, may act as triggers. For some, excitement or stress may play a role too. Negative stress such as anxiety, family problems, etc and the fear of being ill e.g. on a birthday or on holiday can both trigger episodes in some people.
When does it start?
Onset is in childhood, sometimes from birth. Different studies have slightly different results but the peak is between 2-6 years.
How long does an episode last?
Episodes are typically very consistant for any given individual but can vary from a few hours to days between individuals. Most commonly the duration is between 12 hours-2 days. Remember this is the duration of vomiting, sufferers often experience symptoms prior to vomiting including severe nausea, headache, dizziness etc, see Symptoms. Although the families often become expert at recognising the onset of an episode there are few studies which try to quantitate this. It is important to realise that the symptoms even in those with short vomiting durations can be spread over days.
Page last Modified 23/3/02
