Module #5-Path: furncale and carbuncle Flashcards Preview

Pathology Pre-Midterm > Module #5-Path: furncale and carbuncle > Flashcards

Flashcards in Module #5-Path: furncale and carbuncle Deck (35):

Gram Positive Bacteria are considered an exotoxin, what are the gram positive bacteria?

Corynebacteria Diptherae
Actinomyces Israelii


What is the pathogenesis for gram positive exotoxins?



Give an example of a gram positive bacteria exotoxin infection

Toxic Shock Syndrome: intravaginal tampon if left too long leads to growth of staph aureus ---- leads to release of exotoxin in circulation --- leads to conjunctivitis and vomiting


Gram negative bacteria are considered an endotoxin, what are the gram negative bacteria?

N. meningitides
N. Gonorrhoea
Salmonella Typhi
Klebisella, E. coil, Pseudomonas (bronchopneumonia)
Bartonella Henslae


What is the pathogenesis for gram negative endotoxin

Possess a lipopolysaccharide wall (LPS). Bacteria lysis leads to large amounts of LPS in blood --- this binds with lipopolysaccharide binding protein (LBP) forming an LPS-LBP complex --- LPS-LBP is picked by macrophages that release TNF -- damage of endothelium ----- PMNs bind onto damaged epithelium ----release IL-1 procoagulant factor ---DIC


What is the importance of infectious diseases?

Major problem in spite of improved living conditions, vaccinations, antibiotics
More than 10 million deaths/yr in developing countries
New and fatal infections ares still being recognized


What are some barriers to bacterial invasion?

Skin-Keratin Layer
IgA in mucosa, mucus in gut, lungs
Ciliary movement in bronchial passages
Normal Commensals


What are the steps in the diagnosis of infectious disease?

Clinical features: hx, PE
Knowledge of epidemiology: common infections in the geographic area
Isolate the organism: pus, bl, tissue, fluids
Ab response: demonstrate rising titers
Therapeutic response


What are key cells seen in bacterial, viral and fungus infections?

Bacterial: polymorphonuclear Leukocytes
Virus: Macrophages, lymphocytes
Fungus: mixed PMN + lymphocytes + Macrophages + Giant Cells


Bodies response to infection differs depending on the organism. What is the difference between a local and a systemic infection ?

Local: inflammation at the site of infection
Systemic: Response to infection
mediated through cytokines, fever/headache/leukocytosis, increased metabolic rate and memory cells for the future


How can infections spread through the body?

Lymphatics: Lymphadenitis (local and distant)
Venous (regional veins, thoracic duct) -- reach vena cava and R heart ---- right sided valve = endocarditis
Reach the lung and pulmonary artery and produce lung abscess
Through pulmonary veins -- L sided heart (mitral, aortic valve) = endocarditis
Distant abscess: brain, kidney, spleen, brain


What is bacteremia?

Spread of bacteria in blood
--bacteria destroyed by immune system = no symptoms


What is septicemia?

Bacteria in blood multiply
--usually accompanied by fever, chills = serious condition
--can set up distant foci of spread in other tissues = septicemic abscess


What are the steps in a bacterial infection?

Enter the body: ingestion, inhalation, and inoculation
Multiply locally
Spread: lymphatics, blood (plasma, RBC, leukocytes), nerves
Tissue planes, BMs, pleura, pericardium, peritoneum, meninges


What are the types of tissues responses (to damage)?

Acute inflammation: bacterial
Lymph Mononuclear: Virus
Granulomatous: TB
Mixed acute/chronic:Fungus
Eosinophils: parasites
Fibrosis: Schistosoma
Necrosis: Clostridia (Gas gangrene)
Pseudomembrane: diphtheria, Clostridium difficile


What is an example of a gram + enterotoxin and exofoliatintoxins?

Enterotoxin: food poisoning
Exofoliatintoxin: Scaled skin Syndrome


What is folliculitis?

Inflammation/Infection of 1+ hair follicle w/o accessory glands


What is a furuncle (boil)?

Single infected hair follicle + accessory gland
accumulation of pus/dead tissue


What is a carbuncle?

Collection of several furuncles
numerous pus filled w/PMNs, macrophages, necrotic cells
skin --- abscess --- lymphatics ---- venous and other organs


Where is a carbuncle normally found?

Nape of the neck


Carbuncle is typically found in what kind of patients?

Diabetic patients because patients do not heal properly (due to decreased blood flow and polyneuropathy) and they have a lot of glucose that the bacteria is going to feed on


What two bacteria are the most common in a furuncle and carbuncle?

Staph Aureus
Strep Pyogenes


What is the pathogenesis for a furuncle and carbuncle?

Direct damage via enzymes (streptokinase and hyaluronidase)


How does a patient present with a furuncle and carbuncle?

Cardinal signs of inflammation and pus


Diagnosis for carbuncle or furuncle?

History and physical; no biopsy


What would you see on histology for a furuncle or carbuncle?

Liquefactive necrosis or pus with PMNs, macrophages and necrotic cells


What is the healing course for a furuncle or carbuncle?

Most likely outcome is fibrosis because the infection gets down to the dermis (so you will see a scar)


Impetigo is a superficial bacterial skin infection, caused by what two types of bacteria?

Staph. Aureus
Strep Pyogenes


What is the classic sign you see on physical examination on these patients?

Honey colored scabs formed dried serum on an erythematous base


What is the course of impetigo?

Begins as a small pustule that ruptures and leaves an erosion


What patients are most likely going to present with impetigo?

Children, esp kids in daycare and rubbing their face with dirty hands
spread via fomites (aka inanimate objects) from child to child from one side of the cheek to the next
most common on face near mouth and nose


A patent with impetigo, it will resolve with no scar, why?

Because the bacteria only affects the epidermis


What type of hypersensitivity is impetigo?

Type III - immune complex mediated


What is a complication patients can get with Strep Pyogenes in impetigo?

Post streptococcal glomerulonephritis (because this is a type III hypersensitivity) ---- look for hematuria, proteinuria, polyuria, oliguria, HTN and periorbital edema
this is called NEPHRITIC SYNDROME (2-3 weeks)


What additional symptoms can patients have with impetigo?

fever and signs of acute inflammation