Microbial Diseases Of The Skin And Eyes
 
Introduction
Bacterial Diseases
Of The Skin I
Bacterial Diseases
Of The Skin II
 
 
 
Viral Diseases
Of The Skin
Fungal and Parasitic
Diseases Of The Skin
Microbial Diseases
Of The Eye
 

Objectives: Bacterial Diseases of the Skin I

 

For each microbial disease listed give the following if applicable.

Name of the disease
Etiological agent
Transmission of the etiological agent
Signs and symptoms
Clinical diagnosis - How you diagnose the disease.
Laboratory diagnosis - Special laboratory tests used if any.
Pathology - How the organism causes the disease.
Prevention
Treatment

Diseases:

Folliculitis
Sties
Furuncle (boil)
Carbuncles
Impetigo of the new born
Scalded skin syndrome
Toxic shock syndrome

Microbial Diseases of the Skin

Bacterial Diseases of the Skin

 

Staphylococcal Skin Infections

 

Staphylococci are gram-positive bacteria that often grow in clusters.

 

The majority of skin microbiota consist of coagulase-negative S. epidermidis.

Almost all pathogenic strans of S. aureus produce coagulase and catalase.

 

Pathogenic S. aureus can produce enterotoxins, leukocidins, and exfoliative toxin.

 

Many strains of S. aureus produce penicillinase; these are treated with methicillin in some places (not in the U.S. because of the rate of methicillin resistance). Methicillin resistant strains are treated with vancomycin. Vancomycin resistance has been documented and may be treated with a combination of antibiotics but we are on dangerous ground here.

 

Localized infections (sties, pimples, and carbuncles) result from S. aureus entering openings in the skin.

 

Impetigo of the newborn is a highly contagious superficial skin infection caused by S. aureus.

Symptoms - thin-walled vesicles that rupture and crust over

Hexachlorophene skin lotions may be used to prevent outbreaks

Toxemia occurs when toxins enter the bloodstream; staphylococcal toxemias include scalded skin syndrome and toxic shock syndrome.

 

Scalded skin syndrome

Phage present in the strain causes the production of the exfoliative toxin

Disease presents as a lesion around the nose and mouth, then develops into a brightened area and spreads

Frequently seen in children under 2

Treatment with antibiotics (semisynthetic penicillin, cephalosporin, or macrolide/lincosamide)

Scalded Skin Syndrome

Toxic shock syndrome

Considered to be an endogenous infection.

Caused by a toxin produced by some strains.

Toxin binds to class II MHC proteins without intracellular processing. This complex reacts with beta-chain of the T-cell receptor causing the release of large amounts of interleukins (especially 1 and 2). These cause the signs and symptoms.

Symptoms:

Fever

Vomiting

Sunburnlike rash

Shock

Cases are associated with:

Tampons

Nasal surgery in which packing is used

Women who have given birth

Tattoos

Treatment:

Penicillin (most strains are now resistant)

Methicillin (other countries)

Cephalosporins or macrolides (Azithromycin, Clarithromycin [Biaxin], Clindamycin, Telithromycin [Ketek])

Vancomycin

 
Introduction
Bacterial Diseases
Of The Skin I
Bacterial Diseases
Of The Skin II
 
 
 
Viral Diseases
Of The Skin
Fungal and Parasitic
Diseases Of The Skin
Microbial Diseases
Of The Eye