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 is generally excellent with prompt and effective antimicrobial treatment in patients with uncomplicated actinomycosis that does not affect the CNS.
• The factors that define the outcomes of the diesease include
  • Site of infection: the highest mortality is seen if the disease involves central nervous system.
  • The time to diagnosis: delayed presentation results in poorer outcomes
  • The time to the start of appropriate treatment.
• Mortality range from 0% to 28%.( hightest being in CNS)

Complications

Complications that can develop as a result of actinomycosis are

• Extension of disease can result in osteomyelitis of the mandible, ribs, or vertebrae.
• Endocarditis
• Pericarditis
• CNS disease, including brain abscess; chronic meningitis

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

Physical Examination

Vital Signs

• Fever
• Tachypnea

Oral cavity

• Oral ulcers can be seen in some patients
• Poor dental hygiene with dental caries

Lymph nodes

• In cases with skin involvement from direct inoculation, regional lymph node enlargement may be seen.

Neck

• No masses

Cardiovascular system

• Regular rate and rhythm
• Normal S1, S2
• No murmurs, rubs, or gallops

Lungs

Findings consistent with parenchymal consolidation such as

• Dullness to percussion
• Increased fremitus
• Signs of pleura involvement such as pleuritic rub.

Abdominal

• Abdomen soft and non-distended with no scars or striations
• Abdominal mass which is non tender, mostly seen in RLQ.
• abdominal bruits ascultated
• Spleen not palpable, liver not palpable

Skin

• Nodular lesions which gradually increase in size and number resulting in multiple abscesses, and ultimately forming sinuses that open outside.
• Ulcerative lesions that bleed easily

Genitourinary system

• Pyuria
• Painful urination
• Pelvic mass
• Menometrorrhagia

Extremities

• Ulcers that bleed on touch

Neurological

Normal examination finding unless the infection is disseminated to brain resulting in meningitis,then findings include :

• Altered level of consciousness
• Nuchal rigidity

Surgery

Antibiotics are the cornerstone of treatment for actinomycosis, surgical resection is required for infected tissue in cases, especially if extensive necrotic tissue, sinus tracts, or fistulas are present. Surgery is also indicated if malignancy cannot be excluded or if large abscesses or empyemas cannot be drained by percutaneous aspiration. The need for surgery must be assessed on an individual basis. Surgery may be a valid option for patients who do not respond to medical treatment. A retrospective analysis of patients with thoracic actinomycosis showed that surgery cleared the disease in five patients who responded unfavorably to initial antibiotics. Surgery may also be used to control symptoms, as in the control of haemoptysis in thoracic actinomycosis.
Surgical therapy options include

• Incision and drainage of abscesses
• Excision of sinus tracts and recalcitrant fibrotic lesions
• Decompression of closed-space infections