Bacterial toxins and the bodys natural defenses start to break down the bone and connective tissues. The tooth may eventually become loose and have to be removed. Scarlet fever is caused by a particular streptococci species, Streptococci Pyogenes, and is classified be a severe form of bacterial sore throat. The condition involves the release of pyrogenic and erythrogenic endotoxins from the immune system. It starts as tonsilitis and pharyngitis before involving the soft palate and the tongue. It usually occurs in children where a fever occurs and an erythematous rash develops on the face and spreads to most part of the body. If not treated, late stages of this condition may include a furred, raw, red tongue. Treatment options include penicillin and the prognosis is generally excellent.Viral

Herpes simplex (infection with herpes simplex virus, or HSV) is very common in the mouth and lips. This virus can cause blisters and sores around the mouth (herpetic gingivostomatitis) and lips (herpes labialis). HSV infections tend to recur periodically. Although many people get infected with the virus, only 10% actually develop the sores. The sores may last anywhere from 3–10 days and are very infectious. Some people have recurrences either in the same location or at a nearby site. Unless the individual has an impaired immune system, e.g., owing to HIV or cancer-related immune suppression, recurrent infections tend to be mild in nature and may be brought on by stress, sun, menstrual periods, trauma or physical stress. Mumps of the salivary glands is a viral infection of the parotid glands.
This results in painful swelling at the sides of the mouth in both adults and children, which leads to a sore throat, and occasionally pain in chewing. The infection is quite contagious. Today mumps is prevented by getting vaccinated in infancy, by a "Measles, Mumps, Rubella" (MMR) vaccination and subsequent boosters. There is no specific treatment for mumps except for hydration and painkillers with complete recovery ranging from 5–10 days. Sometimes mumps can cause inflammation of the brain, pancreatitis, testicular swelling or hearing loss.Fungal

Oral candidiasis is by far the most common fungal infection that occurs in the mouth. It usually occurs in immunocompromised individuals. Individuals who have undergone a transplant, HIV, cancer or use corticosteroids commonly develop candida of the mouth and oral cavity. Other risk factors are dentures and tongue piercing. The typical signs are a white patch that may be associated with burning, soreness, irritation or a white cheesy like appearance. Once the diagnosis is made, candida can be treated with a variety of anti fungal drugs. Traumatic
Chemical, thermal, mechanical or electrical trauma to the oral soft tissues can cause traumatic oral ulceration. Autoimmune
Sjögren syndrome is an autoimmune chronic inflammatory disorder characterised by some of the bodys own immune cells infiltrating and destroying lacrimal and salivary glands (and other exocrine glands). There are two types of Sjögrens syndrome: primary and secondary. In primary Sjögrens syndrome (pSS) individuals have dry eyes (keratoconjunctivitis sicca) and a dry mouth (xerostomia).