Med Student Corner: My Arm’s on Fire! Or the Clever Masquerade of Cellulitis

Author: Lilamarie Moko, MS4 // Editor: Michael Barrie, OSU EM Attending

It’s another late Thursday night in the ED and the waiting room is backed up with patients needing care. As you finish up with your seventh patient presenting with undifferentiated abdominal pain, your eyes rove the board for something new.  You assign yourself to a gentleman in his 60s, a “John Doe” with left arm swelling. Hopefully his abdomen has been behaving itself…

Upon entering the patient room, you see a pleasant, comfortable appearing gentleman in his mid-60s. He’s been having left arm pain and swelling that started 6 days ago. His arm is “on fire”. He first noticed some redness in his left elbow, associated swelling, tenderness, and restriction flexion and extension of his elbow. After about a day, he noticed the redness spreading down to his left wrist, with similar swelling, tenderness, and restricted flexion and extension of both wrist and fingers. He’s had a temperature to 100F, diaphoresis and chills. Also he reports some diarrhea, and urinary frequency in the past 2 days. With some further probing, he reveals that he just returned from Florida several days ago, had no noted scrapes or wounds, and spent most of his time fishing. He works as a farmer, but hasn’t been working for the past couple weeks.

His past medical history is significant for TIA, basal cell skin cancer, hypertension, osteoarthritis, and gout. He had a right knee replacement several years. He has a remote smoking history of 20 pack-years, and denies regular alcohol intake.

In the room, his vitals are as follows:

T: 99F, HR: 90, BP: 135/80, SpO2: 100% RA, RR:14

His physical exam findings are as follows:

  • Constitutional: comfortable appearing, in no acute distress
  • CV: RRR, no murmurs, rubs, gallops, radial pulses intact b/l
  • PULM: CTAB, no rhonchi appreciated
  • GI: soft, nontender, nondistended
  • MSK/Skin: L forearm—erythema 2 centimeters superior to medial/lateral epicondyle, terminating at the wrist, with erythema increasing in severity closer to wrist. L forearm is tender to palpation and warm to touch. Resistance to passive flexion/extension L elbow and wrist. Limited active flexion/extension L elbow, wrist. R forearm WNL.
  • Neuro: No radial/median/ulnar nerve deficits appreciated to sensation, motor. No gross motor deficits appreciated.


So what’s your differential diagnosis?

As we know, we should always try to eliminate the life-threatening issues first. Now this patient appears comfortable, so index of suspicion is lower for acute life-threatening issues. However many potentially morbid conditions are on our list.

Possible differential:

  • Septic arthritis
  • Septic bursitis
  • Cellulitis – staph, strep, or marine assoicated such as Vibrio species.
  • Gout
  • DVT

When I saw his arm, my first suspicion was cellulitis. However, the rule of the game is to always have an open mind when considering diagnoses for patients.


So let’s discuss cellulitis and the great masquerade.

Cellulitis is characterized by warmth, erythema, and edema at the site of infection, usually a break in the skin barrier. It typically is unilateral, usually restricted to the lower extremity. The course is typically indolent with some localized symptoms. A mild fever may be present. Marine exposures can lead to Vibrio vulnificus infections and other unique marine infections. These can be particularly invasive and are more likely to lead to sepsis.

But when is it not just cellulitis?

  • Watch out for: additional symptoms, like joint swelling and pain, limited ROM—this could be cellulitis with underlying septic arthritis
    • Use synovial fluid sample to diagnose. If the patient has limited passive ROM, then a joint aspiration is indicated. Approach the joint through an area of skin that does not appear to be infected.
  • Watch out for: chronic soft tissue infection refractory to antibiotics—this could be cellulitis with underlying osteomyelitis
    • Use radiographic imaging to diagnose. Xray is a reasonable start, but may need MRI to confirm diagnosis. This diagnosis can generally be made as an outpatient.
  • Watch out for: monoarticular joint pain—this could be acute gout
    • Very difficult to differentiate from septic joints. On synovial fluid analysis would should have crystals, and potentially less WBC than bacterial joint infections. However, there is overlap in their presentation and clinicians should remain vigilant to always consider septic arthritis and not assume gout.
  • Watch out for: history with new skincare products, detergents, with physical exam demonstrating pruritic vesicles, bullae—this could be a “simple” case of contact dermatitis
    • Diagnosis is my history and exam. Treatment is avoiding of allergen and supportive care. Steroids may be indicated in refractor or extreme cases.


Always be aware of these other sneaky diagnoses—missing these might cause further problems down the road!


Back to the story…

After obtaining labs, x-ray of left wrist and elbow, and providing some pain control, ortho was consulted to obtain synovial fluid sample. Synovial fluid analysis showed crystals and less than 10,000 WBC. Smear showed no bacterial, and cultures did results as negative. Because of his atypical gout presentation with fever, redness spreading down his arm, and recent marine exposure, it was determined to also treat him for possible cellulitis with doxycycline to cover marine bacteria.



1. Raff AB, Kroshinsky D. Cellulitis: A Review. JAMA. 2016 Jul;316(3):325-37.

2. Spelman D, Baddour L . Cellulitis and skin abscess: Clinical manifestations and diagnosis. UpToDate Sep 06, 2017.

Med Student Corner: Ankle Pain – Reviewing the Ottawa Ankle Rules

Chief Complaint: Ankle Injury–Does this patient have a fracture?

Author: David Sacolick, MS4 // Editor: Michael Barrie, OSU EM Attending

Musculoskeletal injuries are common chief complaints in both emergency medicine and primary care settings. In particular, over 5 million ankle injuries occur in the United States each year. This patient population includes both young active patients as well as elderly patients. And while ligamentous sprains are more common, fractures are also common and can have long term consequences if not appropriately treated.

When a patient presents with a chief complaint of an ankle injury, how do you answer the question: Does this patient have a fracture? 

A 31 year old female with no significant past medical history presents to the emergency department by squad with a chief complaint of ankle pain.  She reports that she was carrying her newborn baby (in a car seat), and while walking down a flight of stairs she slipped and fell.  She says she stepped on a book with her left foot and fell onto her right ankle. She does not recall if her ankle rolled in or out, but she does remember feeling a pop and being in immediate pain. Fortunately, her young child was unharmed, but the patient was unable to stand and so her parents called 911.

She describes severe pain all around her right ankle, without any numbness or tingling in her foot. She denies any other injuries, and reports no head trauma or loss of consciousness.

Her vital signs are normal, but the patient is in visible discomfort. Her right ankle is swollen and she is tender to palpation at both the medial and lateral malleoli. She does not have pain about her 5th metatarsal or navicular.  She has a 2+ dorsalis pedis pulse and no neurologic deficits in her foot.  She is able to motor her toes but not her ankle. The remainder of her exam is unremarkable.

What is your primary concern with these history and physical exam findings? Does this patient need an X-ray?

This patient’s story and exam findings are concerning for an ankle fracture and she requires an x-ray for further evaluation. While ankle injuries are common chief complaints in an emergency department, a fracture is found in less than 15% of these cases. To address this, the Ottawa Ankle Rules were developed to help determine which patients require radiography. A systematic review of 27 studies reporting on 15,581 patients found the Ottawa ankle rules to be 97.6% sensitive and 39.8% specific for ankle fractures. Importantly, the negative predictive ratio was 0.08, with false negative rate of less than 2%. This means the Ottawa ankle rules are very good at ruling out an ankle fracture.

Ottawa Ankle Rules

  • Inability to walk 4 steps immediately following the injury or in the Emergency Department
  • Tenderness on the posterior edge or tip of medial malleolus
  • Tenderness on the posterior edge or tip of lateral malleolus

The patient in this case had positive findings for all components of the Ottawa Ankle Rules, and her x-ray revealed a trimalleolar fracture of the ankle. Another important teaching point is the utility of full length tib-fib films to rule out a proximal fibular (Maisonneuve) fracture — which in the case of this patient was negative. Orthopaedics was consulted and the patient’s ankle fracture was reduced and splinted with fluoroscopy. She was scheduled for surgical fixation of her ankle fracture.


Take-home point: Ankle injuries are common, and the Ottawa ankle rules are very helpful in determining who needs radiography.



  1. Koehler SM, Eiff P. Overview of Ankle Fractures in Adults. Post TW, ed. UpToDate. Waltham, MA: UpToDate Inc. (Accessed on November 30, 2017.)
  2. Koval, Kenneth J., and Joseph D. Zuckerman. Handbook of Fractures. Lippincott Williams & Wilkins, 2010.
  3. Bachmann LM, Kolb E, Koller MT et-al. Accuracy of Ottawa ankle rules to exclude fractures of the ankle and mid-foot: systematic review. BMJ. 2003;326 (7386): 417.

Fussy Neonate – a Jeopardy game!

Maya S. Iyer, MD, FAAP, Clinical Assistant Professor of Pediatrics, Nationwide Children’s Hospital, Section of Emergency Medicine

Fussy Neonate Jeopardy

This jeopardy game highlights key clinical considerations for infants who present to the emergency department with the chief complaint of fussiness. In particular, the topics highlighted in this game include: fever in the neonate, sudden infant death syndrome (SIDS), brief resolved unexplained events (BRUE) and apparent life threatening events (ALTE), non-accidental trauma (NAT) and a potpourri of other interesting clinical conditions.  The questions require second order thinking. After completing this game, emergency medicine residents should be able to describe the cardinal signs and symptoms, management and possible complications of the above conditions.