Hi thanks for asking question.
Here are few possibility.
1.If you have toothe ache with abscess over gum then it might lead to bacteremia and affection of multiple organ.antibiotic needed for it.
2.Second if you have
abdominal pain, anorexia,weight loss like symptoms
viral hepatitis could be cause.serum viral marker or ultrasound examination done for it.
3.If you have associated cough and fever then respiratory cause like rhinitis , cold,bronchitis etc.has to be thought.antihistaminic with antibiotic needed for it.
4.If predominate bowel problem then
gastroenteritis may be the cause.
Do your complete blood examination.
If
neutrophilia bacterial infection thought and if
lymphocytosis viral infection might be cause.
If bacterial infection suspected antibiotic needed.
I hope my suggestion will help you