Skin and soft tissue infections

Question 1

Normal skin flora

Normal person carry 10^12 bacteria on skin

Answer 1

Gram -ve and Staph viridans, Staph epidermis, Strep diphteroid, Propionobacterium, actinobacter and yeast

Question 2

Bacterial skin infections Cellulitis Impetigo Folliculitis Erysipelas Necrotising fascitis RXs

Answer 2

Cellulitis, Folliculitis, Erysipelas- penicillins or amoxicillin (P, A)
Impetigo- Cephalexin, if topical Fusidic acid or mupirocin (all f7-10d)
Necrotising fasciitis- Benzyl pencillin and clindamycin w/wo Metronidazole

Question 3

Sites of infection of the ff. Cellulitis Impetigo Folliculitis Erysipelas Necrotising fasciitis

Answer 3

Cellulitis- dermis
Impetigo- epidemis due to local invasion of causative agent
Folliculitis- invasion in hair follicles causing minor abcess
Erysipelas- dermis of face
Necrotising fasciitis-soft tissue below the dermis

Question 4

Causative agents of the ff. Cellulitis Impetigo Folliculitis Erysipelas Necrotising fasciitis

Answer 4

Cellulitis, Impetigo, Erysipelas- Strep. pyogenes and Staph aureus
Folliculitis- S. aureus
Necrotising fasciitis- Strep pyogenes (B-hemolytic group A Strep)

Question 5

Tissue below dermis spreading with alarming rapidity along the facial planes causing disruption of the blood supply leading to what? Give all antibiotic txs

Answer 5

Necrotising fasciitis— necrosis and gangrene

Benzyl pen, clinda w/wo Metro in addition to tissue debridment

Question 6

Rapid spreading of the inf. on skin (dermis) Well defined spreading erythematous inflamm, usually accom. by fever and other systemic manifestations.
Give all antibiotic txs

Answer 6

Erysipelas

Tx: P, A. OCCASIONALLY S. AUREUS= w/wo Fluoxacillin

Question 7

Acute spreading of inf. of the dermis. Lesion is hot, red and swollen, edematous. Give all antibiotic txs

Answer 7

Cloxa PO/IV, Amoxi or Cepha 7-10d, Clinda Cotrimox Azith Clarith

Question 8

Bullous, crusted or pustular eruption of the skin. Give all antibiotic txs

Answer 8

Impetigo
Cepha, top fucidic acid or mupi (only top, unique MOA- selectively bind to bacterial isoleucyl-tRNA) and no cross resistance with antibacterial

Question 9

Folliculitis other names

Answer 9

Boil (furuncles), carbuncles

Question 10

A form of necrotising fasciitis occurring around the groin area. Pain, fever, and systemic toxicity, signs of gas formation - prominent factors
What are the main predisposing factors?

Answer 10

Fournier’s gangrene

-Diabetes and local trauma

Question 11

FG causative agents and txs.

Answer 11

Coliform (E. coli), Streptococci (Group A Strep)

Penicillin and Cephalosporin’s if allergic to beta lactams use Quinolones (ciprofloxacin)

Question 12

What skin disease and causative agents for the ff:
Common wart
Fleshy papule
Paplovascular lesions, or skin lesions with systemic spread such as herpes simplex (vesicular lesions)

Answer 12

Skin diseases caused by viruses:
Papilloma virus
Molluscum contagiosum (pox virus)
Pox virus from sheep, goats

Question 13

What skin disease and causative agents:

• Ring worm or skin lesions can be part of systemic manifestation of the disease. (keratin-loving fungi)
• Occurs between toes

Answer 13

Dermatophyte— Cryptococcus neoformans and Blastomyces dermatitidis.