Look at the surface of the leaves. If your plant is indeed infested with spider mites, the leaves may have yellow blotches on them. When light falls on the leaves, you may see a silvered look or even streaks of bronze or silver.
Healthgrades Editorial Staff. White patches in the mouth are a common symptom of infection, inflammation, trauma, malignancy, and other underlying conditions and diseases. Mouth white patches result from pathogens, such as bacteria, viruses and fungi, which inflame the lining of the mouth causing swelling, redness, and ulcer formation.
Symptoms & Signs. Sores or localized abnormalities inside the mouth can arise from a number of causes. Mouth sores can occur on the tongue, gums, lips, or inside the cheeks. They may appear as ulcers or red or white patches in the mouth. Bleeding may sometimes occur if ulceration is severe. Bite injuries to the tongue or inside of the cheek are a common cause of mouth sores.