IMPETIGO

Question 1

A contagious, superficial, intra-epidermal infection occurring prominently on exposed areas of the face and extremities

Answer 1

Impetigo

Question 2

Causes

Answer 2

Staphylococcus aureus alone or combined with group A beta-hemolyticstreptococci

Question 3

A deeper, ulcerated impetigo infection often with lymphadenitis

Answer 3

Ecthyma

Question 4

Most common form of impetigo. Formation of
vesiculopustules that rupture, leading to crusting with a characteristic golden appearance; local lymphadenopathy may occur

Answer 4

Nonbullous impetigo

Question 5

staphylococcal impetigo that progresses from small to large flaccid bullae (newborns/young children) caused by epidermolytic toxin release; ruptured bullae leaving brown crust; less lymphadenopathy; trunk more often affected; <30% of patients

Answer 5

Bullous impetigo

Question 6

Impetigo Risk Factors

Answer 6

(1) Warm, humid environment
(2) Tropical or subtropical climate
(3) Summer or fall season
(4) Minor trauma, insect bites, breaches in skin
(5) Poor hygiene, poverty, crowding, epidemics, wartime
(6) Familial spread
(7) Complication of pediculosis, scabies, chickenpox, eczema/atopic dermatitis
(8) Contact dermatitis
(9) Burns
(10) Contact sports
(11) Children in daycare
(12) Carriage of group A Streptococcus and Staphylococcus aureus
(13) Ecthyma**

Question 7

Diagnostic Tests and Interpretation

Answer 7

(1) None usually necessary in typical presentations; cultures of pus/bullae fluid may be helpful if no response to empiric
(2) Woods lamp and KOH prep to rule out fungal infection in areas of high fungal likelihood

Question 8

Impetigo Treatment

Answer 8

(1) Avoidance of infection spread is the key; hand washing is vital.
(2) Prevent with mupirocin ointment TID to sites of minor skin trauma.
(3) Remove crusts; gentle washing 2 to 3 times daily, clean with antibacterial soap, chlorhexidine, or Betadine.
(4) Washing of entire body may prevent recurrence at distant sites.
(5) Vanilla Staph:
(a) Nonbullous (minor spread, treat 7 days; widespread, treat 10 days); bullous (treat 10 days)
(b) Mupirocin (Bactroban) 2% topical ointment applied TID for 5 to 7 days (nonbullous only)
(c) Dicloxacillin: Adult 250 mg PO QID
(6) MRSA:
(a) Clindamycin, tetracyclines, or trimethoprim-sulfamethoxazole. Oral doses given for 7 days are usually sufficient.
(b) Clindamycin 300 mg q6-8h
(7) Severe bullous disease may require IV therapy such as nafcillin or cefazolin.

Question 9

Differential Diagnosis

Answer 9

(1) Perioral dermatitis
(2) Allergic contact dermatitis
(3) HSV-1/Herpes zoster
(4) Tinea infection

Question 10

Disposition

Answer 10

(1) Full Duty or modified light duty

(2) Dependent on location, distribution, and extent

Question 11

Complications

Answer 11

(1) Ecthyma
(2) Cellulitis
(3) Resistance to treatment
(4) Lymphangitis
(5) Furunculosis