Sandbox:Aditya

Actinomycosis

Classification

Actinomycosis can be classified based on the anatomical site involved into

Epidemiology and Demographics

Incidence

• Actinomycosis is a rare disease.
• Maintaining proper oral hygiene and with widespread use of antibiotics its incidence had been declined
• In 1970, its annual incidence was 1 per 300,000.

Age

Actinomycosis commonly found between 4th to 6th decade of life and very rare in infants and children

Gender

Males are more commonly affected by actinomycosis than females.

Pathophysiology

Transmission

• Actinomyces are part of natural flora of human body,resides in the oral cavity, lower gastrointestinal tract and urogenital tract.
• They are non virulent under normal conditions
• When there is break in the mucosa, anywhere from the mouth to the rectum they reach tissues and cause damage.

	Route of transmission
Cervicofacial	Rupture of mucosa during dental surgeries and poor oral hygiene
Thoracic	Aspiration of inoculum
Abdominal	Disrupture during abdominal surgery or perforated viscus
Pelvic	Placement of IUD

Incubation

Incubation period of Actinomycosis varies from one to four weeks. But occasionally, it may be as long as several months. 

Dissemination

Following transmission, lesions spread by direct extension.

Seeding

• Once the endogenous bacteria are introduced into the tissues, they multiply due to low oxygen tension.
• It triggers an inflammatory reaction which results in formation of hard yellow hard granules(sulfur granules).
• These are solidified bacterial filaments with surrounding tissue exudates.
• Abscesses with fibrous walls and pus along with sulfur granules develop.
• It finally drain out through sinuses.

Immune response

Actinomycosis elicits both humoral and cell-mediated immune responses

Microscopic pathology

• Positive for sulphur granules in pus
• Gram positive organism with branching filaments forming segment-like structures
• Surrounded by neutrophils

Laboratory findings

The gold standard for diagnosing actinomycosis is histological examination and bacterial culture.

CBC

Findings are non-specific and include

• Anemia with mild leucocytosis
• Elevated ESR, and CRP
• Elevated Alkaline phosphatase in hepatic actinomycosis

Culture

• The isolation and identification of Actinomyces can confirm a diagnosis of Actinomycosis.
• The most common clinical specimens employed in isolation are samples of pus, tissue, or sulphur granules
• Cultures are positive between the 7th and 21st day when grown anaerobically at 37C.

Histopathology

• Demonstration of gram positive filamentous organisms and sulphur granules on histological examination is strongly supportive of a diagnosis of actinomycosis.
• Although the presence of sulphur granules is helpful in making the diagnosis, they are not always recovered in culture confirmed cases of actinomycosis.

Natural History

If left untreated, patients with Actinomycosis may progress to develop focal organ involvement with mass-like features and dvelopment of sinus tracts (which can heal and re-form)

Prognosis

• The prognosis of actinomycosis is good with treatment.
• The factors that affect worst outcome of actinomycosis depends on the site of infection, the time to diagnosis, and the time to the start of appropriate treatment
• The highest mortality seen in central nervous system disease. It is therefore crucial to make an early and accurate diagnosis of actinomycosis.
• Mortality range from 0% to 28%.( hightest being in CNS)

Xray Chest

The most common chest radiographic finding tends to be

• Consolidation (usually non-segmental).
• Mass like lesions.

CT Chest

Findings include:

• Patchy air-space consolidation
• Multifocal nodular cavitations associated pleural thickening
• Pleural effusions
• Hilar, and/or mediastinal lymphadenopathy