“Nec Fasc” is one of those diagnoses in medicine that makes surgeons sweat bullets, ER docs pump antibiotics like firehoses, and sends interns screaming into phones to set up emergency surgery STAT. We had a patient where this was a concern, he’d let it go due to the fact he was sooo close to finishing Hellweek as part of his SEAL training- and he made it! But like most guys I’ve seen from this training, they are so cut up, beat down, and pushed so far past their limits you just have to sit back in awe at what they’ve done to their bodies. Stress fracture? That’s nothing! Pneumonia? Who cares! Keep going!
Anyway, I got a few key pointers about telling the difference between nec fasc and cellulitis. These are just things someone educated me about, I didn’t pull this from the 7th edition of a textbook or a randomized controlled double blinded study, so take it for what it is. Cellulitis is MUCH less concerning, though also usually requires hospital admission with antibiotics and can also be devastating in the long run. So here were a couple physical exam pointers that can either raise your blood pressure or calm those 4 AM frayed nerves:
1.) Erythema: Present with both, but in nec fasc the infection in the fascial plane spreads faster than the erythema above it. Therefore, patients often complain of pain beyond the erythematous border. In cellulitis, pain is typically only present over the affected skin.
2.) Palpation: If there’s crepitus, think nec fasc. I’ve felt crepitus before (from a botched chest tube placement) and it seriously feels like there’s crinkled cellophane just below the surface of the skin. Others have described it as rice krispies, which is also close. It actually feels like popping and snapping when you press down! Lack of crepitus doesn’t rule out nec fasc though- it can still be an emergency situation if all you feel is the classic hot, swollen, painful skin. Remember it depends on the organism causing the infection…
3.) Vital signs: Tachycardia may be the only change. Especially in young, healthy patients (like in the military population) their body can compensate for infection for quite a while.. until a sudden crash that was unanticipated lands them in the ICU. On exam, patients can appear to be doing well, but don’t let that fool you! All that “badness” growing at exponential rates will hit a threshold the body can’t handle… and then you’re dealing with full blown Shock. No thanks. Watch your vitals carefully!
4.) Labs: Obviously infection will make your white count go up. However, in the experience of most residents I’ve spoken with, ned fasc will raise it dramatically and usually above 35. Of course, it depends on the time of presentation and immune status of the patient but if the lab starts calling you with critical values, that might be a sign that something critical is happening.
With the SEAL I saw, when I evaluated him in the emergency room, I drew a line at where the erythematous border was though he was already receiving antibiotics. Being on ortho, I was there to rule out compartment syndrome (due to pain out of proportion to exam) but I quickly ruled that out since the skin was pretty soft. Surgery decided to take him to the OR, where I saw him 1.5 hours later and was astounded at how far past my markings the erythema had progressed! He had alredy received about 5 different IV antibiotics and still the infection was advancing. In some places, it was almost an inch. Holy smoke Batman!!!
The surgeon made an elliptical incision over where some new petechiae had shown up on the skin, often being a clue as to where the worst underlying infection may be. I heard him teaching the resident that (only read on if you’re a surgeon or have a strong stomach) …. if it’s nec fasc, expect “dishwater discharge” when making the incision. When palpating the fascia, run your finger up and down the incised areas and if it’s intact, that’s good. If it breaks apart as you push, that’s bad. That’s when you being the unzipping process and debride, debride, debride. Then drink a couple RedBulls and Rockstars because you’re not going to get any sleep on the frequent post-op checks.
My patient did not have nec fasc, in case you’re wondering. They just did the 2 elliptical incisions, packed and left them open, and kept pumping him full of antibiotics and fluids. Phew🙂