ecthyma

^[1]^[2]^[3]

Introduction

Infection of the skin involving the dermis characterized by crusted erosions or ulcerations. A lesion of neglect. Develops in excoriations, insect bites, minor trauma in diabetics, elderly patients, soldiers & alcoholics.

contagious ecthyma is caused by orf virus^[2]
- primary infection of superficial break in skin
  - animal bite^[2]
according to ref^[1]
- Staphylococcus aureus
  - most commonly phage group 2, type 71 same etiologic agent as Staphylococcal scalded skin syndrome
- Streptococcus pyogenes
- primary infection of superficial break in skin
- secondary infection of pre-exsiting dermatosis
- predisposing factors
  - colonization of skin by S aureus & S pyogenes
  - warm ambient temperature
  - high humidity
  - neglect

durations of lesions: weeks to months
painful rash with purulent-appearing papules^[2]
ulceration with thick, adherent hemorrhagic crust
lesions round or oval, may be > 3 cm in size (saucer-shaped)
distribution: ankles, dorsal aspect of feet, thighs, buttocks
- case report shows lesions on hands^[2]
regional lymphadenopathy may be present
often leaves a scar after healing

* images^[2]^[3]

contagious ecthyma^[2]
- routine wound care
- antibiotic agents for possible bacterial superinfection
topical agents
- mupirocin (Bactroban) TID to affected skin & to nares for 7-10 days
- benzoyl peroxide (prevention)
systemic antibiotics
- group A streptococcus (S pyogenes)
  - penicillin VK 250 mg PO TID
  - benzathine penicillin
    - 600,000 units IM (< 6 years of age)
    - 1,200,000 units IM (> 6 years of age)
  - erythromycin 250-500 mg PO QID for 10 days
  - cephalexin 250-500 mg QID for 10 days
- Staphylococcus aureus
  - dicloxacillin 250-500 mg PO QID
  - cephalexin
    - 250-500 mg PO QID for 10 days (adults)
    - 40-50 mg/kg/day for 10 days (children)
  - amoxicillin clavulanate (Augmentin)
    - 20 mg/kg/day divided TID for 10 days
  - macrolides for penicillin-sensitive individuals
    - erythromycin
      - 1-2 g/day divided QID for 10 days (adults)
      - 40 mg/kg/day divided QID for 10 days (children)
    - clarithromycin 250-500 mg PO BID for 10 days
    - azithromycin 250 mg QD for 5-7 days
  - clindamycin
    - 150-300 mg QID for 10 days (adults)
    - 15 mg/kg/day divided QID for 10 days (children)
- methicillin-resistant Staphylococcus aureus (MRSA)
  - mupirocin ointment
  - minocycline 100 mg PO BID for 10 days
  - Bactrim DS 1-2 tabs QD
  - ciprofloxacin 500 mg PO BID

↑ ^1.0 ^1.1 Color Atlas & Synopsis of Clinical Dermatology, Common & Serious Diseases, 3rd ed, Fitzpatrick et al, McGraw Hill, NY, 1997, pg 604-609
↑ ^2.0 ^2.1 ^2.2 ^2.3 ^2.4 ^2.5 ^2.6 Thurman RJ, Fitch RW Images in clinical medicine. Contagious ecthyma. N Engl J Med. 2015 Feb 19;372(8):e12 <PubMed> PMID: https://www.ncbi.nlm.nih.gov/pubmed/25693031 <Internet> http://www.nejm.org/doi/full/10.1056/NEJMicm1304779 (case report, images)
↑ ^3.0 ^3.1 ^3.2 Elkston CA, Elkston DM Bacterial Skin Infections: More Than Skin Deep. Medscape. July 19, 2021 https://reference.medscape.com/slideshow/infect-skin-6003449