Skin Infections

Question 1

Staphylococcus Aureus

Answer 1

Gram (+) Cocci
Catalase positive
Coagulase positive
Ferments mannitol
Hemolyses blood (BAP)
Nose and skin

Question 2

Folliculitis

Answer 2

Staphylococcus Aureus

Small red bump, or pimple that develops at the site of a hair follicle

Question 3

Furuncle

Answer 3

Staphylococcus Aureus

An abscess in the skin oftentimes containing pus

Question 4

Carbuncle

Answer 4

Staphylococcus Aureus
A painful localized infection of the skin and subcutaneous tissues that usually has several openings through which pus is discharged

Question 5

Scalded Skin Syndrome

Answer 5

Staphylococcus Aureus
Superficial layers of the epidermis slough in response to exfoliatin toxin 
Predispose to secondary infections
Particular problem in immune compromised
Treatment by: 
Isolation of patient
Penicillinase resistant penicilllins
Removal of dead skin

Question 6

Scalded Skin Syndrome

Answer 6

Staphylococcus Aureus
Superficial layers of the epidermis slough in response to exfoliatin toxin 
Predispose to secondary infections
Particular problem in immune compromised
Treatment by: 
Isolation of patient
Penicillinase resistant penicilllins
Removal of dead skin

Question 7

Streptococcus Pyogenes

Answer 7

Gram (+) Cocci

Catalase Negative

Question 8

Rickettsia Rickettsii

Answer 8

Rocky Mountain Spotted Fever
Obligate intracellular organism
Transmitted by the bite of an infected tick.
The rickettsia in tick are in a dormant state and must be activated by the warm blood meal and released into the saliva of the tick. Thus, prolonged exposure to an infected tick must occur.
(Spiders)

Question 9

Rocky Mountain Spotted Fever

Answer 9

R.Rickettsii infect endothelial cells lining the small blood vessels by parasite-induced phagocytosis.
Pathogenesis is primarily due to destruction of the cells by the replicating bacteria. Destruction of the endothelial cells results in leakage of blood and subsequent organ and tissue damage due to loss of blood into the tissue spaces. Endotoxin often released into the bloodstream (septic shock).
Symptoms begin with the abrupt onset of fever, chills headache and myalgia (muscle pains) usually 2-12 days after the tick bite. Rash usually (90% of cases) appears 2-3 days later. The rash begins on the hands and feet and spreads centripetally towards the trunk. Rash on the palms and soles is common.
Treatment
Prevention: repellents, removal of ticks
R. rickettsii is susceptible to tetracyclines and
chloramphenicol.
Mortality is ~20% if left untreated

Question 10

Rocky Mountain Spotted Fever

Answer 10

R.Rickettsii infect endothelial cells lining the small blood vessels by parasite-induced phagocytosis.
Endotoxin often released into the bloodstream (septic shock).
Symptoms: abrupt onset of fever, chills headache and myalgia (muscle pains) usually 2-12 days after the tick bite. Rash usually (90% of cases) appears 2-3 days later.
Treatment:
Prevention: repellents, removal of ticks
R. rickettsii is susceptible to tetracyclines and
chloramphenicol.

Question 11

Borrelia Burgdorferi

Answer 11

Lyme Disease
A tick bite leads erythematous skin rash (erythema migrans) in a few days along with a transient bacteremia leading to (weeks or months later) severe neurologic symptoms or polyarthritis.
Cardiac problems may occur
Early antibiotic therapy, leads to cure
Late antibiotic administration (penicillin or tetracycline) is often ineffective.

Question 12

Borrelia Burgdorferi

Answer 12

Lyme Disease
A tick bite leads erythematous skin rash (erythema migrans) in a few days along with a transient bacteremia leading to (weeks or months later) severe neurologic symptoms or polyarthritis. (Spider)
Cardiac problems may occur
Early antibiotic therapy, leads to cure
Late antibiotic administration (penicillin or tetracycline) is often ineffective.