Oral herpes. The most common symptom of oral herpes, caused by the herpes simplex virus, is cold sores. Oral herpes can also cause fever and muscle aches. Mouth sores most commonly occur in children aged 1-2 years, but they can affect people at any age and any time of the year.ral herpes causes. Herpes simplex is a DNA virus that causes sores in and around your mouth. Two herpes subtypes may cause these sores. 1  Herpes simplex virus type 1, or herpes-1, which causes around 80% of cases of oral herpes infections. 2  Herpes simplex virus type 2, or herpes-2, which causes the rest.
The main symptoms of viral gastroenteritis are watery diarrhea and vomiting. Other symptoms of gastroenteritis include headache, fever, chills, and abdominal pain. The symptoms may appear within hours or a few days of infection. They usually last for 1 to 2 days, but may last as long as 10 days.
Depending on the cause, viral gastroenteritis symptoms may appear within one to three days after you're infected and can range from mild to severe. Symptoms usually last just a day or two, but occasionally they may persist as long as 10 days. Because the symptoms are similar, it's easy to confuse viral diarrhea with diarrhea caused by bacteria, such as Clostridium difficile, salmonella and E. coli, or parasites, such as giardia.