ORAL MEDICINE Dr. Ali Al-Ibrahemy

INFECTIOUS DISEASES OF ORAL MUCOSA

A- VIRAL INFECTIONS

1- Primary Herpetic Stomatitis

Primary infection is caused by Herpes simplex virus, usually type I, which in the

non-immune person (not exposed to the virus previously), can cause an acute

vesiculating stomatitis. However, most primary infections are subclinical.

Therefore, recurrent (reactivation) infections usually take the form of herpes

labialis (cold sores or fever blisters). Transmission of herpes virus is by close

contact and up to 90% of inhabitants in large, and urban communities, develop

antibodies to herpes virus during early childhood. In many British and US cities,

by contrast approximately 70% of 20 year olds may be non-immune, because of

lack of exposure to the virus. In more rich countries the incidence of herpetic

stomatitis has declined and it is seen in adolescents and adults, rather than

children. It is more common in the immunocompromised, such as HIV infection

when it can be persistent or recurrent. The two major types, HSV1 and 2, can be

distinguished serologically or by restriction endonuclease analysis of the nuclear

DNA. Classically, HSV1 causes a majority of cases of oral and pharyngeal

infection, meningoencephalitis, and dermatitis above the waist; HSV2 is

implicated in most genital infections. Although this distinction applies to a

majority of cases, changing sexual habits are making that distinction less

important. Both types can cause primary or recurrent infection of either the oral

or the genital area, and both may cause recurrent disease at either site.

Clinical featuresThe early lesions are vesicles which can affect any part of the oral mucosa,

the hard palate and dorsum of the tongue are favoured sites. The vesicles are

dome-shaped and usually 2-3 mm in diameter. Rupture of vesicles leaves

circular, sharply defined, shallow ulcers with yellowish or grayish floors and red

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margins. The ulcers are painful and may interfere with eating. The gingival

margins are frequently swollen and red, particularly in children, and the

regional lymph nodes are enlarged and tender. There is often fever and systemic

upset, sometimes severe, particularly in adults. Oral lesions usually resolve

within a week to ten days, but malaise can persist so long that an adult may not

recover fully for several weeks.

Diagnosis and treatmentThe clinical picture is usually distinctive. A smear showing virus-damaged

cells is additional diagnostic evidence. A rising titre of antibodies reaching a

peak after 2-3 weeks provides absolute but retrospective confirmation of the

diagnosis. Acyclovir (200-400 mg, for seventh days) is a potent anti-herpetic

drug and is life-saving for potentially lethal herpetic encephalitis or

disseminated infection. Acyclovir suspension used as a rinse and then swallowed

should accelerate healing of severe herpetic stomatitis if used sufficiently early.

Bed rest, fluids and soft diet may sometimes be required, local anaesthetic

before meal helped children to eat the foods. Systemic non-steroidal anti-

inflammatory drug needed to control the fever and pain and reduce the

exacerbations of inflammation of this disease ( such as profinal 200mg tab. or

syrup ). Metronidazole helped to control the secondary infections such as the

gingivitis.

2- Herpes LabialisAfter the primary infection, the latent virus can be reactivated in 20-30%

of patients to cause cold sores (fever blisters). Triggering factors include the

common cold and other febrile infections, exposure to strong sunshine,

menstruation or, occasionally, emotional upsets or local irritation, such as dental

treatment. Neutralizing antibodies produced in response to the primary

infection are not protective.

Clinically, changes follow a consistent course with prodromal paraesthesia

or burning sensations, then erythema at the site of attack. Vesicles form after an

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hour or two, usually in clusters along the mucocutaneous junction of the lips, but

can extend onto the adjacent skin. The vesicles enlarge, coalesce and weep

exudates. After two or three days they rupture and crust over but new vesicles

frequently appear for a day or two only to scab over and finally heal, usually

without scarring. The whole cycle may take up to 10 days. Secondary bacterial

infection may induce an impetiginous lesion which sometimes leaves scars.

TreatmentIn view of the rapidity of the viral damage to the tissues, treatment must

start as soon as the premonitory sensations are felt. Acyclovir cream is available

without prescription and may be effective if applied at this time. This is possible

because the course of the disease is consistent and patients can recognize the

prodromal symptoms before tissue damage has started. However, pencyclovir

applied 2-hourly is more effective.

3- Herpetic WhitlowBoth primary and secondary herpetic infections are contagious and cause

herpetic cross-infections called Herpetic whitlow which is a recognized

uncommon hazard to dental surgeons and their assistants. Herpetic whitlows, in

turn, can affect patients and have led to outbreaks of infection in hospitals and

among patients in dental clinics. Now that gloves are universally worn when

giving dental treatment, such cross-infections should no longer happen. In

immunodeficient patients, such infections can be dangerous but acyclovir has

dramatically improved the prognosis in such cases and may be given on

suspicion. Mothers applied antiherpetic drugs to children’s lesions should wear

gloves.

4- Herpes Zoster (Trigeminal area)Zoster (shingles) is characterized by pain, a vesicular rash and stomatitis.

The varicella zoster virus caused chickenpox in the non-immune persons

(mainly children), while reactivation of the latent virus causes zoster, mainly in

the elderly. Unlike herpes labialis, repeated recurrences of zoster are very rare, 3

occasionally, there is an underlying immunodeficiency. Herpes zoster is a hazard

in organ transplant patients and can be an early complication of some tumours,

particularly Hodgkin’s disease, and increased in AIDS cases and potentially

lethal.

Clinical featuresHerpes zoster usually affects adults of middle age or over but occasionally

attacks even children. The first signs are pain, irritation and tenderness in the

dermatome (skin and mucosa) corresponding to the affected ganglion. Vesicles,

often confluent, form on one side of the face and in the mouth up to the midline.

The regional lymph nodes are enlarged and tender. The acute phase usually lasts

about a week. Pain continues until the lesions crust over and start to heal, but

secondary infection may cause suppuration and scarring of the skin. Malaise

and fever are usually associated.

ManagementHerpes zoster is an uncommon cause of stomatitis, but readily

recognizable. According to the severity of attack, oral acyclovir (800 mg five

times daily for 7 days) should be given at the earliest possible moment, together

with analgesics. The addition of oral corticosteroids such as prednisolone may

accelerate relief of pain and healing. In immunodeficient patients, intravenous

acyclovir is required and may also be justified for the elderly in whom this

infection is debilitating. Post-herpetic neuralgia mainly affects the elderly and is

difficult to relieve, and the pain is more variable in character and severity than

trigeminal neuralgia. It is typically persistent rather than paroxysmal. Post-

herpetic neuralgia is remarkably is resistant to treatment. Nerve or root

resection are ineffective and the response to drugs of any type, including

carbamazepine (Tegretol), is poor. Application of transcutaneous electrical

nerve stimulation (TENS) to the affected area by the patient himself for several

times in day, is sometimes effective, by persistent stimulation the sensory

pathways, so may prevent perception of pain centrally.

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5- Cytomegalovirus-Associated UlcerationCytomegalovirus (CMV) is a member of the herpes virus group. Up to

80% of adults show serological evidence of CMV infection without clinical

effects but it is a common complication of immunodeficiency. Particularly AIDS.

In the latter it can be life-threatening. Oral ulcers in which CMV has been

identified are sometimes clinically indistinguishable from recurrent aphthae,

other have raised, minimally rolled borders. Generally, the ulcers are large,

shallow and single, and affect either the masticatory or non-masticatory mucosa.

Sometimes oral ulcers are associated with disseminated CMV infection. The

virus present in oral lesions may merely be a passenger, but their causative role

is suggested by reports of response to gancyclovir.

6- Hand-Foot-and-Mouth DiseaseThis common, mild viral infection which often causes minor epidemics

among school children, is characterized by ulceration of the mouth and a

vesicular rash on the extremities. Hand-foot-and-mouth disease is usually caused

by strains of Coxsakie A virus. It is highly infectious, frequently spreads through

a classroom in schools and may also infect a teacher or parent. The incubation

period is probably between 3-10 days. Foot-and-mouth disease of cattle is a quite

different, rhinovirus infection, which rarely affects humans but can also cause a

mild illness with vesiculating stomatitis.

Clinical featuresThe rash consists of vesicules, sometimes deep-seated, or occasionally

bullae, mainly seen around the base of fingers or toes, but any part of the limbs

may be affected. The rash is often the main feature and such patients are

unlikely to be seen by dentists. In some outbreaks either the mouth or the

extremities alone may be affected.

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Treatment Serological test confirm the diagnosis. The disease is typically resolves

within week. No specific treatment is available, but myocarditis or encephalitis

are rare complications.

7- Acute Specific FeversFevers which cause oral lesions are rarely seen in dentistry. Those which

cause vesicular rashes (chickenpox) produce the same lesions in the mouth. In

the prodromal stage of measles, koplik’s spots form on the buccal mucosa and

the soft palate and are pathognomonic. Palatal petechiae or ulceration, involving

the face especially are seen in glandular fever and are accompanied by the

characteristic, usually widespread lymphadenopathy.

8- Kawasaki’s Disease (Mucocutaneous Lymph Node Syndrome)

kawasaki’s diseas is endemic in Japan but uncommon in British. It is

frequently unrecognised and has caused significant mortality. Though its

epidemiology suggests that it is an infection, this has not been established.

Clinical featuresChildren are affected and have persistent fever, oral mucositis, ocular and

cutaneous lesions, and cervical lymphadenopathy. Oral lesions consist of

widespread mucosal erythema with swelling of the lingual papillae (strawberry

tongue).

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