CRACKED OR COATED TONGUE
A healthy tongue is pink, moist and covered with tiny white dots called papillae. A lack of saliva can lead to dryness and cracks. You can also get a white or black coating due to a fungal infection; if that persists it may suggest diabetes, as high glucose in saliva leads to an overgrowth of a yeast called Candida albicans. Antibiotics can also trigger fungal infection.
“Antibiotics kill good and bad bacteria and when good bacteria are knocked out the bad bugs overtake your mouth,” explains Creeper. Try anti-fungal medications and probiotics, which have been shown to help.