Micp

• Skin lesions


  • Vesicle
  • Bulla
  • Macule
  • Pustule
  • Papule
  • Plaques
  • Nodules
  • Urticaria (Wheals and Hives)
  • Petechiae
  • Purpura
  • Ecchymosis

  
• Vesicle


  Small fluid-filled blister on the skin that is less than 5 mm in diameter
• Vesicle


  • Chicken pox
• Bulla


  A fluid-filled sac that appears when fluid is trapped under a thin layer of the skin. It is also a type of blister but it is more than 5 mm in diameter
• Macule


  A flat skin lesion, a small patch of skin that is altered in color

  
• Pustule


  A small bump on the skin that contains pus
• Papule


  A flat with elevated surface. A solid palpable lesion that is less than or equal to 5 mm in diameter. They can be solitary or multiple
• Plaques


  Are flat with elevated surface that is more than 5 mm in diameter
• Nodules


  Are rounded raised lesions more than 5 mm in diameter
• Urticaria (Wheals and Hives)


  Annular or ring-like papules or plaques with pinkish in color. They are seen in allergic reactions
• Petechiae


  Skin bleeding lesions with less than 3 mm in diameter. They are seen in dengue patients
• Purpura


  Skin bleeding lesion greater than 3 mm in diameter. They are seen in Meningococcemia patients

  
• Ecchymosis


  Skin bleeding lesion with greater than 3 mm in diameter. They are also known as "Black eye"
• Outline


  • I. SKIN BACTERIAL INFECTIONS
  • A. SKIN LESIONS
  • B. STAPHYLOCOCCUS AUREUS
  • C. STAPHYLOCOCCUS EPIDERMIDIS
  • D. STREPTOCOCCUS PYOGENES
  • E. PSEUDOMONAS AERUGINOSA
  • F. CLOSTRIDIUM PERFRINGES
  • G. BACILLUS ANTHRACIS
  • II. OCULAR BACTERIAL INFECTIONS
  • III. FOODBORNE DISEASES
  • IV. MOUTH INFECTIONS
• Staphylococcus aureus


  Gram-positive round-shaped bacterium, usually arranged in grape-like clusters, a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin, the most dangerous of all of the many common staphylococcal bacteria
• Staphylococcus aureus


  • Produces enzymes & toxins for its pathogenicity and through direct invasion and destruction of tissues
• Mode of transmission for Staphylococcus aureus skin infections

  • Direct contact with person having purulent lesions
  • From hands of healthcare hospital workers
  • From fomites like bed linens, contaminated equipment
• Clinical findings for Staphylococcus aureus

  • Folliculitis
  • Furuncle
  • Carbuncle
  • Sty/Hordeolum
  • Impetigo
  • Staphylococcus Scalded Skin Syndrome (SSSS)
• Folliculitis


  A pyogenic (pus-producing) infection involving the hair follicles, a common skin condition, characterized by localized painful inflammation that heals rapidly after draining the pus
• Furuncle


  AKA Boils, an infection of several hair follicles that has a small collection of pus (called an abscess) under the skin, an extension of folliculitis, characterized by larger and painful nodules with underlying collection of dead and necrotic tissue
• Carbuncle


  A red, swollen, and painful cluster of boils that are connected to each other under the skin, represents a coalase of furuncles that extends into the subcutaneous tissue with multiple sinus tracts
• Sty/Hordeolum


  Involves one or more of the small glands near the base of the eyelids, it is red & painful, often filled with pus
• Impetigo


  Infection common in young children and primarily involves the face and limbs, starts as macule which later becomes a pus filled vesicle that ruptures and forms honey-colored crust, can also be caused by Staphylococcus pyogens
• Staphylococcus Scalded Skin Syndrome (SSSS)

  Aka Ritter's Disease, primarily found in newborns and young children, manifestations include exfoliative toxin responsible for the disease, only the outer layer of the skin is affected hence no scarring, sudden onset of perioral erythema or bullous (redness) that covers the whole body within 2 days, positive Nikolsky sign, bullae and cutaneous blister, desquamation

  
• Laboratory diagnosis for Staphylococcus aureus

  • Microscopic examination of Gram-stained specimen (gram positive cocci)
  • Culture (gray to golden colonies)
  • Catalase positive (aerobic bacteria)
  • Coagulase positive (clots plasma)
• Treatment and prevention for Staphylococcus aureus

  • Treatment of choice: beta lactam antibiotics
  • Develops resistance to penicillin derivatives like methicillin and nafcillin, oxacillin is the only penicillin derivative antibiotic that has remained active
  • Incission and drainage (I & D)
  • Use Standard Precautions for skin, burn, and wound infections if they are minor
  • Contact Precaution if major SSSS
  • Standard Precautions for infections caused by methicillin-resistant S. aureus (MRSA), add Contact Precautions if wounds cannot be contained by dressing
• Staphylococcus epidermidis


  Part of the normal flora of the skin, associated with "stitch abscess", UTI and endocarditis, it causes infections in individuals with prosthetic devices, cardiac devices CNS shunts
• Streptococcus pyogenes


  Gram positive cocci arranged in pairs or chains, belongs to Groups A beta hemolytic, major virulence factor is M protein which is anti-phagocytosis, produces enzymes and toxins responsible for the pathogenicity, some strains are encapsulated, maybe associated with severe systemic infections
• Clinical findings for Streptococcus pyogenes

  • Pyoderma (Impetigo)
  • Erysipelas
  • Cellulitis
  • Necrotizing Fascitis
• Pyoderma (Impetigo)


  A purulent skin infection that is localized and commonly involves the face, the upper and lower extremities, starts as vesicles then progresses to pustules, the lesion ruptures and forms honey-colored crusts, there maybe enlargement of the regional lymph nodes but no sign of systemic infection

  
• Erysipelas


  AKA St. Anthony's fire, superficial form of cellulitis, follows a respiratory or skin infection, affects the upper dermis and extends into the superficial cutaneous lymphatics, manifestations include localized raised areas associate with pain, erythema, warmth, lymphadenopathy, systemic manifestations

  
• Cellulitis


  Involves the skin and SC tissue, the infected skin and the normal skin are not clearly differentiated, local inflammation with systemic signs

  
• Necrotizing Fascitis


  AKA 'flesh-eating" infection or streptococcal gangrene, involves deep SC tissue, starts as cellulitis then becomes bullous and gangrenous, it spreads to the fascia then the muscle and fat, it may become systemic and cause multi-organ failure to death
• Complications of Streptococcus pyogenes

  • Acute Glumerolous Nephritis
  • Rheumatic Fever
  • Scarlet Fever/Scarlatina
• Acute Glumerolous Nephritis


  Commonly associated with skin infections

  
• Rheumatic Fever


  Associated with throat infections, non-supporative, immune mediated complications
• Scarlet Fever/Scarlatina


  Develops in some people who have strep throat, manifested by Strawberry tongue, bright red rash that covers most of the body, sore throat and fever
• Laboratory diagnosis for Streptococcus pyogenes

  • Microscopy (gram-positive cocci in pairs and chains associated with leukocytes)
  • Culture (positive beta hemolysis in blood agar)
  • Bacitracin test (antibiotic susceptibility test with posituve zone of inhibition of growth around the Bacitracin disc)
• Treatment and prevention for Streptococcus pyogenes

  • Treatment of choice: Penicillin
  • In case of penicillin allergy, macrolides (erythromycin, azithromycin) or cephalosporins are alternate drugs
  • The drainage of pus and thorough debridement of infected tissues
• Pseudomonas aeruginosa


  An opportunistic aerobic gram-negative bacillus that is frequent & common cause of nosocomial infection, capable of water-soluble pigments (pyocyanin-blue), resistant to most antibiotics, virulence is attributed to adhesins (flagella, pili, LPS), toxins (exotoxin A, pigments) & enzyme