cold abscess

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COLD ABSCESS Dr. P.Sudheer kumar Orthopaedics postgraduate Narayana medical college & hospital

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Tuberculosis

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Page 1: Cold abscess

COLD ABSCESS

Dr. P.Sudheer kumarOrthopaedics postgraduate

Narayana medical college & hospital

Page 2: Cold abscess

Introduction

An Abscess is a collection of pus within the body.

It is cold because it is not accompanied by the classical signs of inflammation

Almost always a sequel of tubercular infection anywhere in the body commonly in the lymph nodes & bone.

Page 3: Cold abscess

Pathogenesis

Any osteoarticular tubercular lesion is a result of a hematogenous dissemination from a primarily infected visceral focus

Primary focus may be in Lungs,lymph glands of mediastinum/mesentry/cervical region or kidneys or other viscera.

Phagocytosis of tubercle bacilli by RES

Page 4: Cold abscess

Pathogenesis

The characteristic microscopic lesion is the tuberculous granuloma– a collection of epithelioid and multinucleated giant cells periphery.

Within the tubercle, small patches of caseous necrosis appear. These may coalesce into a larger yellowish mass, or the centre may break down to form an Abscess.

Page 5: Cold abscess

Pathogenesis

Polymorpho nuclear cells

Macrophages & monocytes

Langhans giant cellsCentral caseation

necrosis

Cold abscess

Page 6: Cold abscess

Histology

Page 7: Cold abscess

Pathology

It is formed by collection of products of liquefaction & the reactive exudation

It penetrates the ligaments in articular disease, bone & periosteum in osseous disease

Migrates in various directions following the path of least resistance along fascial planes,blood vessels and nerves, to distant sites

Page 8: Cold abscess

Composition

Mostly composed of -serum -leucocytes -caseous material -bone debris -tubercle bacilli

Page 9: Cold abscess

Sites

Commonly at Neck & Axilla

Also at Groin,back,side of chest wall

These are sequel of tubercular infection of spine,ribs & posterior medistinal group of lymph nodes.

Page 10: Cold abscess

Clinical features

Painless Swelling -insidious onset

-soft & smooth mass

-cystic consistency

-fluctuation present

-slip sign negative

-No transillumination

Page 11: Cold abscess

Clinical features… Sinus or ulcer

superadded infection with pyogenic organisms

Constitutional symptoms like low grade fever, cough , weight loss,loss of appetite

Symptoms of primary tuberculosis

Page 12: Cold abscess

Clinical features… Local Pressure effects due to swelling

c-spine: exudate collects behind prevertebral fascia & protrude as retropharyngeal abscess causing dysphagia, dysphonea, hoarseness of voice & respiratory obstruction

abscess may track down to enter trachea, esophagus or pleural cavity. It may spread laterally into the sternomastoid muscle & forms an abscess in the neck.

Page 13: Cold abscess

Clinical features… T-spine: exudate confined locally as

paravertebral abscess

it may enter into spinal canal & compress spinal cord leading to Early onset pott’s paraplegia

it can penetrate anterior longitudinal ligament to form mediastinal abscess .

pass downwards through medial arcute ligament to form a lumbar abscess.

Page 14: Cold abscess

Clinical features… Lumbar spine -abscess can have pus track

along the psoas muscle towards the groin & presents as psoas abscess

Flexion deformity of hip can develop due to it.(pseudo hip flexion)

Can gravitate beneath inguinal ligament to appear on the medial aspect of thigh

exudate can follow vessels to form an abscess in scarpa’s triangle or gluteal region

Page 15: Cold abscess

Differential diagnosis

Pyogenic abscess

Lipoma

cyst

Soft tumors

Page 16: Cold abscess

Investigations

Lab studies

Microbiology studies to confirm diagnosis

Radiological diagnosis

Page 17: Cold abscess

Lab studies

Mantoux / Tuberculin skin test

ESR may be markedly elevated (neither specific nor reliable).

ELISA : for antibody to mycobacterial antigen-6 , sensitivity of 60% – 80%.

PCR

Page 18: Cold abscess

Fnac & Biopsy

Percutaneous , CT scan ; guided needle biopsy of bone lesions is a safe procedure that also allows therapeutic drainage of large paraspinal abscesses

Biopsy is confirmative

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Microbiology studies to confirm diagnosis

• Ziehl-Neelsen staining: Quick and inexpensive method.

• Bone tissue or abscess samples

stain for acid-fast bacilli (AFB), & isolate organisms for culture & drug susceptibility.

• Culture results - few weeks. • Positive only in 50% of cases.

Page 20: Cold abscess

Radiological diagnosis

1. PLAIN RADIOGRAPH 2.ULTRASOUND 3. CT SCAN 4. MRI SPINE 5.BONE SCAN

Page 21: Cold abscess

Plain Radiograph

Cervical region - b/w vertebral bodies , pharynx and trachea Upper thoracic - ‘V’ shaped shadow , stripping lung apices laterally and downwards Below T4 – fusiform shape (bird nest

appearence) Below diaphragm – unilateral / bilateral

psoas shadow

Page 22: Cold abscess

Plain Radiograph…

Page 23: Cold abscess

ULTRASOUNDDetect cold abscess A HYPO ECHOEIC LESIONInternal echoes represent debris within. Guided aspiration

Page 24: Cold abscess

CT IMAGE

Patterns of bony destruction.Calcifications in abscess (pathognomic for Tb)

Page 25: Cold abscess

MRI •Assessment of extradural abscesses / subligamentous spread.•Skip lesions•Spinal cord involvement.

Page 26: Cold abscess

Radionucleotide Scan T 99m Increased uptake in up to 60 per cent

patients with active tuberculosis.

Avascular segments and abscesses show a cold spot due to decreased uptake.

Highly sensitive but nonspecific.

Aid to localise the site of active disease and to detect multilevel involvement

Page 27: Cold abscess

TREATMENT

Anti tubercular drugs Aspiration Ultrasound guided Pigtail catheter

drainage Surgical management

Page 28: Cold abscess

ANTI TUBERCULAR DRUGS

Same as tuberculosis elsewhere in the body. The chemotherapy is continued for 18 months.

Drug:                                     Dosage:                           Side effects: 

Rifampicin:                             450-600mg                        Liver toxicity

 

Isoniazid   300-450mg                     peripheral neuritis

 

Pyrizanamide:                        40mgms/kg     Liver toxicity.

hyperuricemia

Ethambutol:                           15-25mgms/kg.                  Optic neuritis.

Streptomycin(inj) 20mgms/kg vestibular damage,

nephrotoxicity

Page 29: Cold abscess

Aspiration

•Palpable Cold abscess must be drained as early as possible & instil 1gm Streptomycin +/- INH in solution

•Technique: Zig-Zag aspiration using Wide bore needle from non-dependent area to prevent sinus formation

Page 30: Cold abscess

Ultrasound guided Pigtail catheter drainage

Page 31: Cold abscess

Surgical

Open drainage may be performed if aspiration failed to clear it.

Drainage using non-dependent incision,later closure of wound without placing a drain

Correcting underlying bony lesion/defect.

Page 32: Cold abscess