Cellulitis – Clinical Image and Ultrasound

cellulitis

Case Presentation

A 45-years-old male with a week history of right leg swelling and redness presented to the ED. He has type II DM and hypertension. He denies fever; however, complaints about burning pain over the skin. Vitals were 156/98 mmHg blood pressure, 98 beats per minute heart rate, 16 respiration per minute, 36.7 degrees Celsius temperature and 98% oxygen saturation in room air. Physical exam revealed erythema over the right medial lower leg and calf area (images). Minimally painful with palpation. The area was hot compared to the left leg. Other examination findings were unremarkable.

Cellulitis 2

Cellulitis 1

Patients with red, swollen, painful leg may have very severe problems such as necrotizing fasciitis (infection involving muscular fascia) or infections involving muscles with or without gangrene. The patients having these infections are generally ill-looking, severely painful, and may have subcutaneous crepitations. Therefore, we should be aware of these red flags. This patient has no sign of crepitations, systemic illness, or severe pain.

Lipodermatosclerosis is chronic erythema. Patients show exacerbations because of vascular insufficiency (venous). It can be bilateral or unilateral. One of the discriminative findings from cellulitis is temperature over the lesion. Lipodermatosclerosis is not hot. In the case, the palpation showed warm skin compared to the left side.

Erysipelas is superficial and its’ borders are very sharp. The lesion is fluffy compared to the skin around the lesion. In the case, some areas of the skin were found a little bit raised compared to surrounding structures. However, its’ borders were not well-demarcated.

Other differentials are burns, contact dermatitis, urticaria, etc.

Bedside ultrasound imaging can help to identify cellulitis, abscess, foreign body, fracture, etc. Cobblestone finding is a typical finding for cellulitis.

Bedside ultrasound imaging was performed with Butterfly iQ with soft tissue settings. Cobblestone finding was found in the erythematous areas. This is a nonspecific finding and can be seen many different soft tissue infections. There were no gas/air artifacts (necrotizing fasciitis) or obvious abscess formation. However, there was a minimal fluid accumulation, which creates a suspicion of an abscess. In the case, there was no air artifact. However, x-rays can also help to show air accumulation in soft tissues.

An Example for Necrotizing Fasciitis

The ultrasound investigation in this video shows the air (white) artifacts in the soft tissue.

X-ray Image Showing Subcutaneous Air in Necrotizing Fasciitis

Case courtesy of Dr Matt Skalski, Radiopaedia.org. From the case rID: 25026

For mild uncomplicated patients – dicloxacillin, amoxicillin, and cephalexin are common choices.

If the patient has a penicillin allergy – clindamycin or a macrolide (clarithromycin or azithromycin) can be used.

Fluoroquinolones should be reserved for gram-negative organisms’ sensitivity defined by culture results because of their additional toxicity risks.

For more antibiotic options and explanations, please visit – here

The patients with co-morbidities compromising immune response, periorbital or perianal locations, unable to tolerate oral medication, deep infections should be admitted.

References and Further Reading

  • Loyer EM, DuBrow RA, David CL, Coan JD, Eftekhari F. Imaging of superficial soft-tissue infections: sonographic findings in cases of cellulitis and abscess. AJR Am J Roentgenol. 1996 Jan;166(1):149-52. PubMed PMID: 8571865.
  • Shyy W, Knight RS, Goldstein R, Isaacs ED, Teismann NA. Sonographic Findings in Necrotizing Fasciitis: Two Ends of the Spectrum. J Ultrasound Med. 2016 Oct;35(10):2273-7. doi: 10.7863/ultra.15.12068. Epub 2016 Aug 31. PubMed PMID: 27582527.
Cite this article as: Arif Alper Cevik, "Cellulitis – Clinical Image and Ultrasound," in International Emergency Medicine Education Project, December 2, 2019, https://iem-student.org/2019/12/02/cellulitis-clinical-image-and-ultrasound/, date accessed: December 11, 2019

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