Impacted teeth usually tends to apply pressure on the overlying soft tissue, which is your gums. When this happen, it’ll result in 2 things.
1. Pericoronitis/ inflammation of the gums over the impacted tooth
2. Fibrosis/ thickening of the gums over it which might look whitish.
Best thing would be to consider removal of the impacted wisdom tooth as it might cause future problems with such presentation.
Next Steps
Visit a dentist and consult a oral and Maxillofacial surgeon for tooth removal
Health Tips
Try salt water gargling if pain persists.