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.
Oral thrush causes thick white or cream-colored deposits, most commonly on the tongue or inner cheeks. The lesions can be painful and may bleed slightly when they are scraped. The infected mucosa of the mouth may appear inflamed and red. Oral thrush is caused by species of Candida fungus.