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.
White, cream-coloured, or yellow spots in the mouth. The spots are slightly raised. There is normally no pain in the area underneath the spots. If you scrape off these spots, they leave small wounds that bleed slightly. In adults, thrush can cause an uncomfortable burning sensation in the mouth and throat.