Skin Infections & Antibiotics

Skin infections are a really common chief complaint in urgent care. Cellulitis, animal bites, abscesses, you name it. My last shift had all three, including a severe case of cellulitis, which was rapidly progressing, and had to be admitted for IV broad spectrum antibiotics.

It’s important to know which bacteria are associated with each infection as your antibiotic must cover for it. This past month, I had a case of a cat bite that was initially treated with Cephalexin, pt came in to our urgent care couple of days after with tactile fever, chills, and hypotension. Pt was quickly out of urgent care, referred to our adjacent ER & later admitted for sepsis 2/2 (secondary to) cat bite. Yikes!
 
So, all in all, make sure you know which antibiotics to choose from & know when skin infections should be referred to the ER
 
Thanks to HippoEd for all the wonderful lessons. What I give you here is just a snippet of their amazing lectures, be sure to check them out on the link below: 

• HippoEd: Urgent Care Boot Camp

 
Cellulitis

• Don’t confuse stasis dermatitis with cellulitis. Stasis dermatitis is often bilateral
• Important bacteriology: streptococcus is most common cause. Consider staph if infection is purulent
• Consider an ultrasound to r/o abscess—all pus must drain!
• Tx: 
  • Cephalexin alone for cellulitis
  • Dual coverage: Cephalexin and TMP-SX
  • Clindamycin for pen allergic patients

​Cat/Dog bites: 

• Cat bites have a higher tendency to become infected
• Time to onset of infection
  • Dog bites: 24 h
  • Cat bites 12 h 
• Important Bacteriology: Pasteurella Multicida (along with other mixed flora--staph, strep)

Human bite

• If you see a laceration over a knuckle—treat as a fight bite, no matter what the patient may tell you. This is a fight bite until proven otherwise! (side note: there is actually a really good medicolegal case about a fight bite that was missed. Check out: Urgent Care Rap which is also by HippoEd)
• Important Bacteriology: Eikenella (along with mixed flora--staph, strep)

 
Treatment for animal/human bites

• Augmentin covers Pasteurella & Eikenella, also covers strep & staph. Remember: it does not have MRSA coverage, however MRSA is less common amongst bite infections
• Prophylaxis: Augmentin 875 BID x 3 days
• Treatment: Augmentin 875 BID x 7 days
• Pen allergic: Doxycycline or Moxifloxacin

Bounce backs:

• Bounce-backs for skin infections often occur due to incorrect antibiotic coverage or presence of abscess that must be drained
• Consider changing antibiotics if no improvement after 48 hours
• Give patients detailed return/ER precautions

 
When to transfer to ER?

• An important aspect of urgent care medicine is knowing when a patient needs to be referred for higher level of care to the emergency room
• If you’re suspecting necrotizing fasciitis—pain out of proportion to exam, hemorrhagic bulla, systemic toxicity, gas formation. These pts have to be out of UC and immediately sent to ER
• Consider transfer if: 
  • Rapid progression, systemic toxicity or metabolic instability—fever, chills, tachycardia, hypotension, confusion, hyperglycemia, azotemia
  • Reminder: Don’t disregard abnormal vitals!

 
​Check back next week for another installment of urgent care Boot Camp Fridays—not sure yet which topic I’ll be going over next week, so if you have any suggestions let me know below~