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.
Canker sores appear inside the mouth. They usually are small ulcers. (minor aphthous ulcers) with a white, yellow or gray center and a flat. red border. Rarely, canker sores can be very large (major aphthous. ulcers) with a raised border.