ACTINOMYCOSIS

ACTINOMYCOSISIt is a chronic, suppurative granulomatous disease

caused by a fungus-like organism Actinomyces Israelii. It is an anaerobic gram-positive filamentous

organism. It has been established that A Israelii may be

recovered from the oral mucosa, tonsillar crypts, dental cavities and pharynx of many normal persons.

The method of infection is not definitely known. Entry into the tissue is resumed to result from trauma

or ulceration or by tooth extraction.

It is not known whether additional factors like hypersensitivity is necessary for subsequent evolution. The actinomyces grow in the human tissue in the form of yellow colonies which are easily seen in the pus as ‘sulphur granules’ by the naked eye. When these granules are crushed under a cover glass and examined unstained, two elements may be distinguished – branching mycelial elements and club forms.

The filaments are gram-positive and constitute greater part of the body, whereas the clubs are gram-negative pear-shaped bodies which form a fringe around the periphery of the colony of the body. The filaments are arranged in radiate fashion from the centre part of the granule. The characteristic radial arrangement is responsible for the familiar term ‘ray fungus’.The clubs probably represent a means of defence against the invading organism.

Three clinical forms of actinomycosis are encountered. In more than half the cases the initial lesion involves the tissues of the face and neck including the mandible, in the remainder cases the lungs and the gastrointestinal tract are involved with equal frequency. The basic pathology is a subacute pyogenic inflammation with considerable induration and multiple sinus formation.

1. FACIO-CERVICAL ACTINOMYCOSIS

The lower jaw is more frequently involved, which may be adjacent to a carious tooth.

A firm mass slowly develops.

It is characteristically seen over the angle of the mandible.

It is frequently painless.

CONTINUE…..

The connective tissue, the muscle and the bone are successively destroyed and replaced by granulation tissue.

An abundant fibrous tissue reaction may lead to brawny induration in the affected area.

Gradually softening occurs at few places with appearance of abscesses, which ultimately burst to form multiple sinuses.

So the overlying skin becomes indurated and bluish in colour with openings of numerous sinuses.

The pus is usually thin and contains sulphur granules which are diagnostic.

2. IN THE ABDOMINAL

In the ABDOMINAL form, mainly the caecum or appendix is affected.

In the submucosa flat grey nodules appear, which turn into a large firm mass, readily mistaken for malignancy.

Suppuration within it forms multiple abscesses.

CONTINUE…..

Ultimately the abdominal wall is involved with multiple sinuses discharging thin pus with sulphur granules.

The liver is the second organ affected by this disease.

It is involved either by direct extension or by blood borne infection through portal vein.

The lesion is a honey-comb mass within the liver which resembles a sponge saturated with pus.

3. LUNGSLUNGS are involved by direct

spread from the neck downwards or from abdomen upwards.

Lungs may be affected by aspiration of the fungus.

The lung becomes riddled with abscess cavities surrounded by abundant fibrous tissue.

Gradually the chest wall may be involved with multiple sinuses.

SPREAD

Actinomycosis is not known to spread. Sometimes the lesion may rupture into a vessel to

cause blood borne metastases in distant organs e.g. the liver, the brain, the heart, kidney, spleen and ovary.

Spread by lymphatics is unknown.

TREATMENT A. Israelii are sensitive

to penicillin, lincomycin and tetracycline.

If penicillin is used a prolonged intensive course should be given 10 mega units daily in the beginning reducing to 4 mega units daily later on.

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