التسمم الدموي والحالات المميتة

Faculty of Oral and Dental Medicine

• Aspires to be a leading educational institution regionally and internationally, through advanced educational programs, innovative applied research, and sustainable community development.

Vision

• The Faculty of Oral and Dental Medicine aims to be a recognized educational institution, both regionally and internationally.

Mission

• The mission is to prepare well-trained dentists committed to human values and professional ethics.
• This will be achieved by developing advanced educational programs tailored to the needs of the local and global labor market.
• The Faculty is also committed to developing applied research aligned with national strategies and providing sustainable community service based on international quality standards.

Student Learning Outcomes (SLOs)

• Students will be able to define and describe the etiology, pathogenesis, pathologic features, and effects of toxemia, bacteremia, septicemia, and pyemia.
• Students will be able to discuss the pathology of tuberculosis (mode of transmission, tissue reaction, types, spread).
• This includes tuberculosis of the lung, tonsils, lymph nodes, bones, intestine, peritoneum, joints, kidneys, nervous system, and skin.
• Students will be able to discuss the pathology of leprosy, sarcoidosis, syphilis, and actinomycosis.

Toxaemia

• Definition: Toxaemia is the presence of bacterial toxins circulating in the bloodstream.
• Toxins can be categorized as endotoxins or exotoxins.
• Endotoxins: mainly produced by gram-negative bacteria.
• Exotoxins: mainly produced by gram-positive bacteria, such as those that cause cholera, diphtheria, and tetanus.
• Manifestations: include constitutional signs (fever, rigors, headache, weakness, loss of appetite), degeneration of organs (cloudy swelling, fatty degeneration), acute heart failure, necrosis and hemorrhage of the suprarenal gland, anaemia, acute respiratory distress syndrome, and septic shock with disseminated intravascular coagulation (DIC).

Bacteraemia

• Definition: the transient presence of bacteria in the blood without toxic manifestations
• Pathogenesis: bacteria enter the blood from a septic focus (e.g., tonsillitis, sinusitis, or following dental extractions) or during the incubation period of some infections.
• Fate: bacteria are usually engulfed by phagocytic cells. Occasionally, bacteria may localize to cause acute osteomyelitis, renal abscesses, or subacute bacterial endocarditis

Septicaemia

• Definition: the circulation and multiplication of large numbers of virulent bacteria and their toxins in the blood, leading to a highly fatal condition.
• Causes: Septicaemia can be caused by highly virulent bacteria in the course of infected operations, septic wounds, puerperal sepsis, large abscesses, or cellulitis.
• Pathological features: severe toxaemia with severe constitutional signs; petechial hemorrhages in skin, mucous membranes, and serous membranes; degeneration and focal necrosis in some organs; acute adrenal insufficiency; serofibrinous inflammation of serous sacs; acute bacterial endocarditis; acute splenic swelling; septic shock; and ARDS and DIC

Pyaemia

• Definition: the circulation of septic emboli in the blood, with their arrest in various tissues leading to multiple small localised abscesses.
• Types:
  • Systemic pyaemia: arises from pulmonary infections, lung abscesses, or bacterial endocarditis, leading to emboli lodging in the kidneys, spleen, and brain.
  • Pulmonary pyaemia: arises from cases of puerperal sepsis, osteomyelitis, or cellulitis, resulting in emboli arresting in the lung.
  • Portal pyaemia: arises from acute suppurative appendicitis, acute cholecystitis or infected piles, resulting in the emboli arresting in the liver.

Tuberculosis

• Definition: a chronic infective granuloma caused by Mycobacterium tuberculosis (tubercle bacillus).
• Methods of infection:
  • Inhalation
  • Ingestion
  • Inoculation
• Tissue reaction:
  • Proliferative tissue reaction: occurs with first contact with human tissue and characterized by tubercle formation. Multiple tubercles fuse to appear as small greyish yellow foci with a yellowish caseous center., composed of epithelioid cells, Langhan's giant cells, and lymphocytes.
  • Exudative tissue reaction: occurs with second contact with sensitised human tissues containing T-lymphocytes; manifests as rapid formation of tubercles, rapid caseation of tubercles, and rapid liquefaction of caseous material.
• Types:
  • Primary pulmonary tuberculosis (usually in children) results from inhalation of M. tuberculosis, initially resulting in Ghon's focus, tuberculous lymphangitis and lymphadenitis.
  • Secondary pulmonary tuberculosis (usually in adults) results from reactivation/new infection and typically involves chronic fibrocaseous pulmonary tuberculosis, with apical lesions, acinar lesions, insignificant nodal lesions, or tuberculosis bronchopneumonia, and miliary tuberculosis.
• Spread of tuberculosis: Direct spread, lymphatic spread, blood spread (isolated organ, miliary), and intracanalicular spread.

Sarcoidosis

• Definition: a granuloma characterized by tubercle-like lesions, without caseation, of unknown etiology
• Pathology/Sites: lesions affecting skin, lymph nodes, lungs and liver.
• Microscopic Appearance/Micro: small, rounded, non-caseating tubercles made up of epithelioid cells, lymphocytes, and Langhans giant cells. Inclusion bodies may be present (Schwanmann and Asteroid bodies).
• Outcome/Healing: lesions heal via fibrosis

Leprosy

• Definition: a chronic infective granuloma caused by Lepra bacilli.
• Gross Morphology: nodular masses less than 1 cm, called lepromas.
• Microscopic Morphology: granulomas formed primarily from macrophages, lymphocytes, and plasma cells. Macrophages engulf lepra bacilli, and multiple bacilli inside them result in vacuolated cells (lepra cells).
• Types: Nodular leprosy (Lepromatous Leprosy) presenting lesions of skin, nasal, nerve, trophic, and visceral tissues

Actinomycosis

• Definition: a chronic infective suppurative granuloma caused by the anaerobic Gram-positive bacterium Actinomyces isrealii.
• Gross Morphology: multiple intercommunicating abscesses opening onto the surface via multiple sinuses, discharging pus and yellowish colonies.
• Microscopic Morphology: bacterial colonies in the center are surrounded by acute and chronic inflammatory cells. Granulation tissue forms at the periphery, followed by fibrosis.
• Types: cervico-facial, pulmonary, intestinal, and skin

Fungal (Mycotic) Diseases

• Mycetoma pedis/Madura Foot: a chronic infective suppurative granuloma caused by Nocardia fungus, common in India. Clinical features involve inflamed, swollen feet with multiple sinuses draining pus and yellowish, brownish, or blackish fungal colonies and tissue destruction, including bone.
• Histoplasmosis: a fungal infection caused by Histoplasma capsulatum. Characterised by inhalation of spores, leading to lung, lymph nodes, liver, and spleen involvement, manifesting as focal necrosis in lesions surrounded by lymphocytes, macrophages, and occasional giant cells; fibrosis and dystrophic calcification.

Moniliasis/Candidiasis

• Definition: a yeast infection caused by the Candida albicans fungus.

• Infection: endogenous (commensal), occurs in immunocompromised or debilitated individuals due to prolonged antibiotic use.

• Pathology:

• Superficial: oral thrush (whitish, patchy plaques); vaginal lesions; interdigital; and paronychia (nail lesions).

• Invasive: esophageal and intestinal candidiasis; disseminated candidiasis (immunosuppressed, high mortality)

Viral Infections

• Nature: Obligatory intracellular parasites
• Introduction to the body: inhalation, ingestion, inoculation, bite of animal
• Pathological features: Cellular degeneration and necrosis; cellular proliferation; cellular inflammatory reaction; inclusion bodies (in some).

Viral Infections (Specific examples)

• Measles: Reddish maculo-papular skin rash; upper respiratory tract catarrh; giant cell and lymphoid tissue hyperplasia.
• CMV (Cytomegalovirus): Multisystem affection in immunosuppressed; pneumonitis, hepatitis, enterocolitis, retinochoroiditis.
• German measles (Rubella): Macular skin rash; generalized lymph node enlargement; splenomegaly; congenital malformations.
• Mumps: Inflammation and swelling of the parotid gland.
• AIDS (Acquired Immunodeficiency Syndrome): a retroviral disease characterized by multisystem manifestation.