Bacterial Skin Infections - JD

Question 1

Folliculitis

Answer 1

Papular or pustular inflammation of hair follicles with purulent material in the epidermis

Question 2

Furuncle

Answer 2

Painful, firm or fluctuant abscess originating from a hair follicle “boil” purulent material extends through dermis to Sub-Q tissue

Question 3

Carbuncle

Answer 3

A network of furuncles connected by sinus tracts. Purulent drainage

Question 4

Cellulitis

Answer 4

Painful, erythematous infection of dermis and Sub-Q with poorly demarcated borders

Question 5

Erysipelas

Answer 5

Fiery red, painful infection of superficial skin (dermis) with sharply demarcated borders

Question 6

Impetigo

Answer 6

Large vesicles and/or honey-crusted sores, contagious, superficial bacterial skin infection

Question 7

Impetigo is common in what population?

Answer 7

common in infants & children (2-5 y.o.)

Question 8

What are the differences between Non-bullous impetigo and Bullous impetigo?

Answer 8

1) Non-Bullous: pustule rupture exposes red, moist base. Honey-yellow to white-brown adherent crust forms
- Heals without scarring
- Staph/Strep
- Children/Adults

2) Bullous: Flaccid bullae filled with clear yellow fluid turns to turbid and brown. Rupture bullae leave thin brown crust.
- Common on trunk
- Always S. aureus
- Scarring is possible
- Infants/preschool

Question 9

What is the Tx for a patient with impetigo?

Answer 9

• Usually self-limiting so treat symptoms
• Wash with anti-bacterial soap to remove crust
• Bactroban BID x 5-7 days
• PO Abx → Cephalexin
• if MRSA → Doxy, Bactrim
• Limit exposure to others

Note: May have post-strep glomerulonephritis

Question 10

What is the difference in the level of infection between Erysipelas and Cellulitis?

Answer 10

Erysipelas → epidermis & dermis

Cellulitis → dermis & subcutaneous tissue

Question 11

What are the causative agents of Erysipelas and Cellulitis infections?

Answer 11

• GABHS (S. pyogenes)
• S. Aureus
• MRSA
• Other G (-) aerobes and fungi (rarely)

Question 12

What are S/S of Erysipelas & Cellulitis?

Answer 12

• Red, hot, swollen, tender, edema
• swollen or tender lymph nodes
• chills and fevers
• Erysipelas: superficial lymphatic involvement
• Cellulitis: slower course present with or without purulent drainage/exudate

Question 13

What are treatment options for Erysipelas/Cellulitis?

Answer 13

Erysipelas: PCN
Cellulitis: Pen V, augmentin
MRSA: Clinda/Doxy/Bactrim
-Mild (PO) → Severe (IV)

Question 14

What is a potential pitfall of cellulitis Tx?

Answer 14

Necrosis: weakened tissue will not be perfused → no Abx will get to site

If no improvement → consider surgical debridement

Facial Cellulitis → vision loss

Necrotizing Fasciitis → flesh eating bacteria

Question 15

What organism is associated with cat/dog bites, and how is it treated?

Answer 15

• Pasteurella multocida

- Tx: Augmentin 875 mg BID x 10 days

Question 16

What is the treatment for a patient with Bartonella Hens (cat scratch disease)?

Answer 16

-Macrolide (azythro) or Doxy

Question 17

What vaccines should you consider giving to a patient who has suffered a dog bite?

Answer 17

Tetanus and Rabies vaccines

Question 18

What are the characteristics of a Folliculitis skin lesion and what are the common pathogens causing it?

Answer 18

• Superficial infection of hair follicle with purulent material in epidermis.
• Begins as thin, yellowish-white pustules with a hair coming out the middle
• Pathogens: Staph & Pseudomonas Aeruginosa

Question 19

What medication may precipitate folliculitis?

Answer 19

Corticosteroids (steroid acne)

Question 20

What are treatment options for Folliculitis?

Answer 20

• Good skin hygiene
• Topical Abx (Bactroban)
• If deeper infx → cephalexin or dicloxacillin

Question 21

What do furuncles and carbuncles evolve from?

Answer 21

Staphylococcal folliculitis

Question 22

Hidradenitis Suppurativa is a recurring abscess of what gland?

Answer 22

-Apocrine gland (axilla, perianal, groin, perineum)

Question 23

What are the clinical manifestations of Staphylococcal Scalded Skin Syndrome (SSSS)

Answer 23

• Blisters, fever, desquamation, pain, erythema
• Diffused sheetlike desquamation
• Positive Nikolsky’s sign (slight rubbing of skin results in exfoliation and wet appearance of skin)

Question 24

What is the Tx for SSSS?

Answer 24

Oxacillin or nafcillin

Possibly Vancomycin if MRSA suspected

Question 25

What is the Tx for decolonization of nasal MRSA?

Answer 25

Intranasal topical Mupirocin (Bactroban) BID x 5 days & Chlorhexidine baths 5-14 days