Dreams dictionary: Splinter
Dreams dictionary: Interpretation 1
To dream that you have a splinter suggests that you are letting petty and trivial matters upset you. As a result, you are hindering your own progress. Try not to take other's opinions and remarks personally.
Dreams dictionary: Miller Dream Interpretation
To dream of splinters sticking into your flesh, denotes that you will have many vexations from members of your family or from jealous rivals. If while you are visiting you stick a splinter in your foot, you will soon make, or receive, a visit which will prove extremely unpleasant. Your affairs will go slightly wrong through your continued neglect.