A 12-year-old male with a history of autism spectrum disorder and chronic sinusitis presented for forehead swelling. His mother reported that she noticed progressive forehead swelling for about one month. She had followed up with the patient’s pediatrician and ENT and was given oral cephalexin and fluticasone nasal spray which did not make any changes in his symptoms. The patient denied any fevers or headaches.
A 25-year-old female with no pertinent past medical history presented to an emergency department in Massachusetts with four days of generalized malaise, myalgias, congestion, low-grade fever, and a rash behind her left knee. The patient denied cough, shortness of breath, chest pain, abdominal pain, nausea, vomiting, and diarrhea. She lives with three roommates, none of whom were sick, and she denied any other known sick contacts. She also denied any occupational exposures or recent travel, although did endorse some recent hiking in the area.
A 21-year-old otherwise healthy female presented to the Emergency Department with a fever after recently returning from Ghana. She reported intermittent fever, headache with photophobia, diarrhea, joint pains, and generalized weakness. She also noticed a diffuse, intermittently pruritic rash on her trunk and extremities. While in Ghana, she volunteered at a refugee hospital, ate street food, and was exposed to local animals. Prior to her stay in Ghana, she spent a week in Bali. She reported receiving vaccines before leaving but was unsure which vaccines she received.
Vitals: Temp 102.9°F; HR 126; BP 114/78; RR 18; O2 sat 98% on room air
General: Uncomfortable-appearing with her eyes closed on initial exam.
HEENT: PERRL, EOMI, Normal conjunctiva without erythema; Full ROM of neck without neck stiffness/rigidity.
GI: Abdomen soft, non-tender, nondistended. No palpable masses, hepatomegaly or splenomegaly.
MSK: No evidence of joint effusion, erythema or tenderness.
Skin: Diffuse maculopapular rash to all four extremities and chest with confluent erythema noted in some areas intermixed with small areas of spread skin, scattered papules around the ankles consistent with mosquito bites.
White Blood Cell (WBC) Count: 2.78 k/mm3
Hemoglobin: 12.9 gm/dL
Hematocrit: 38 %
Platelets: 125.3/mm3
ESR: 10 mm/hr
CRP: 9.37 mg/L
AST: 42 U/L
ALT: 58 U/L
This is a case of Dengue Fever. This diagnosis should be considered in a returning traveler from an endemic region (i.e., Asia, India, Latin America, Africa) with a fever above 40°C, retro-orbital headache, myalgias, nausea, vomiting, and/or rash. The characteristic rash associated with dengue is described as “islands of white in a sea of red”, with confluent erythema and small areas of spared skin. A bedside tourniquet test can also be performed by inflating a blood pressure cuff around the upper arm for five minutes at a pressure halfway between the patient’s systolic and diastolic blood pressure. This test is deemed positive if more than 10 petechiae are present within a square inch of skin, suggesting capillary fragility.
Although mild cases of dengue can be treated supportively, more severe cases typically require hospitalization. Some warning signs of severe disease include abdominal pain or vomiting, hepatomegaly, signs of volume overload including ascites or pleural effusion, and an increase in hematocrit with rapid thrombocytopenia. Severe dengue can present with shock, volume overload, severe bleeding, encephalopathy, and liver failure. Emergency physicians must keep a broad differential when evaluating fever in return travelers and prioritize history and physical exam findings to help narrow the diagnosis and provide appropriate management and supportive care while awaiting further confirmatory testing.
A 26-year-old male with a past medical history of eczema presented to the Emergency Department with a rash for two days. The patient stated he first noticed a rash on his right arm that rapidly spread to his face, chest, and left arm. He reported having similar rashes before but never to this extent. The patient stated he was given Bactrim and amoxicillin about one month ago for another rash, though he was unsure of the diagnosis. He denied any known allergies or exposures to new foods or hygiene products. He had no chest pain, SOB, nausea, or diarrhea. He lives in a correctional facility and does not know of anyone with any rashes.
Vitals: Temp 102.7°F; BP 134/81; HR 137; RR 17; O2 100% on room air
Cardiac: Tachycardic, no murmurs
Lungs: CTABL
Skin: Pustular vesicles with scattered areas of confluency on face, upper extremities and torso. Yellow crusting on face, no mucosal involvement.
WBC: 17
Platelets: 261
Blood cultures: One of two positive
CMP and UA WNL
Non-bullous Impetigo
Impetigo is a rash that effects the epidermis. There are two main types, bullous and non-bullous. S. Aureus and S. Pyogenes are the most common causes of non-bullous impetigo with S. Aureus accounting for up to 80% of cases. Impetigo is highly contagious and patients often self-inoculate other areas of their skin after the initial lesion develops. As papules develop, they fill with pus and once ruptured a classically characterized honey-colored crust is left on the skin. It is more common in immunocompromised patients, diabetics, patients with poor hygiene, and those patients who spend time in crowded dwellings such as daycare or prison. Systemic antibiotics are recommended in all cases of bullous impetigo and in non-bullous impetigo if there are more than five lesions, signs of deeper tissue involvement, or systemic symptoms as was the case with this patient. Beta-lactamase-resistant antibiotics such as Keflex or Augmentin are often the first line and if the patient resides in an area with a high prevalence of MRSA, doxycycline or clindamycin are recommended. Once diagnosed, it is important to wash any clothing, bedding, or infected surfaces to prevent further household or community spread. In the case of this patient, he developed systemic symptoms ultimately becoming septic, and required admission with IV antibiotics. He made a full recovery.
Group A Strep Infection. (n.d.). Group a Strep Infection. https://www.cdc.gov/group-a-strep/?CDC_AAref_Val=https://www.cdc.gov/groupastrep/diseases-%2520hcp/impetigo.html
A 50-year-old male with insulin-dependent Type 2 Diabetes presented to the emergency department with three days of pain and swelling on the right side of his neck. He endorsed progression of his symptoms, reporting that he was now having fevers, myalgias, and intermittent difficulty swallowing solid foods.
Vitals: BP 153/96; HR 110; T 100.0°F; RR 16; O2 sat 97%
General: Appears uncomfortable
HEENT: Mild right-sided facial swelling. No trismus. No gingival inflammation or swelling or induration to suggest abscess. There is focal swelling and tenderness to palpation, without overlying erythema, throughout the right submandibular triangle, and along the sternocleidomastoid.
MSK: Limited active right shoulder range of motion secondary to pain
WBC: 10.4
Hgb: 14.4
Plts: 213
Na: 131
K: 3.7
A1C: 13
Lemierre syndrome (LS) is a rare complication of bacterial pharyngitis/tonsillitis and involves an extension of the infection into the lateral pharyngeal spaces of the neck with subsequent septic thrombophlebitis of the internal jugular vein (as seen on CT). Patients may present with trismus, dysphagia, and fever. Due to the possibility of widespread septic emboli, patients may experience sequelae of systemic infection with dyspnea, focal neurologic deficits, and abdominal pain. Treatment consists of prompt antibiosis and rapid source control.
Most cases of bacteremia in Lemierre syndrome are caused by Fusobacterium necrophorum, an anaerobic gram-negative rod that colonizes the oropharynx. This bacterium causes platelet aggregation and thrombus formation through hemagglutinin production and direct activation of the coagulation cascade. However, up to one-third of patients are found to have a polymicrobial infection with streptococcus and staphylococcus species frequently present.
Read this tutorial on the use of point of care ultrasonography (POCUS) for pediatric soft tissue ultrasonography. Then test your skills on the ALiEMU course page to receive your PEM POCUS badge worth 2 hours of ALiEMU course credit.
Wendy is a 7-year-old girl who comes into the emergency department with redness, swelling, and pain on her left calf. Her symptoms started 1 week ago as a scratch which progressively got more red and painful. There has been no drainage from the lesion. She has had no fevers, but endorses elevated temperatures of 99 F.
On arrival, her vital signs are:
| Vital Sign | Finding |
|---|---|
| Temperature | 100.1 F |
| Heart Rate | 95 bpm |
| Blood Pressure | 105/68 |
| Respiratory Rate | 20 |
| Oxygen Saturation (room air) | 100% |
Figure 1. Linear ultrasound transducer
Figure 2. Left: Water bath technique; Right: Ultrasound of a toe using a water bath (image courtesy of The Pocus Atlas and Moudi Hubeishy, MD)
Figure 3. Normal soft tissue layers on ultrasound (image courtesy of The Pocus Atlas)
Normally on a soft tissue ultrasound, you will see layers of defined structures separated by fascial planes.
Cellulitis has a spectrum of appearances on ultrasound. Early cellulitis may present as skin thickening (Figure 4).
Figure 4. Cellulitis with skin thickening
As cellulitis progresses, there is effacement of the clearly differentiated structures seen above, and the tissue layers may appear hazy and hyperechoic. More advanced cellulitis may have “cobblestoning” which is the result of edematous fluid separating fat globules in the subcutaneous tissue.
Figure 5. Cellulitis with cobblestoning
Abscesses can have varied appearances. They can be anechoic (black) or filled with debris leading to a heterogeneous appearance of contents. The rim may be echogenic or blend in with surrounding tissue. They may be well-circumscribed or may have irregular borders.
 A. Abscess with irregular borders and heterogeneous appearance |  B. Well-circumscribed abscess with heterogeneous debris |  C. Larger abscess with well-circumscribed borders |
 D. Abscess with irregular borders and surrounding cellulitis |  E. Abscess with irregular borders and more homogenous appearance |  F. Superficial abscess with well-circumscribed borders |
Placing color Doppler flow on a suspected abscess is helpful to differentiate it from a lymph node or blood vessel (see “Abscess Mimickers” section for lymph node examples). It may also aid in identifying nearby vasculature.
Figure 6. Abscess with color Doppler flow
Abscesses may exhibit posterior acoustic enhancement, which results in an enhanced transmission of ultrasound waves through a fluid-filled structure. Sometimes the abscess may not be as obvious and appear less anechoic due to debris. A squish (or swirl) sign may be elicited by putting pressure on the region, which will cause movement of the abscess contents. This finding has also been called “pus-talsis”.
Figure 7. Abscess with posterior acoustic enhancement
Abscesses should be measured in 2 planes. Measure depth in 1 plane and length in 2. An easy way to remember this is to measure a plus sign (+) in one view, and a minus sign (-) in the other.
Figure 8. Measurement of abscess in two planes (images courtesy of Dr. Munaza Rizvi)
Lymph nodes appear as ovid and well-circumscribed structures on ultrasound and may be confused for abscesses. They may be differentiated by their homogenous echotexture, central echogenic hilum. When inflamed, they may exhibit internal vascularity which should not be seen in an abscess.
Figure 9. A lymph node with a hilum (left) and a reactive inguinal lymph node with central vascularity (right)
Cysts are fluid-filled, well-circumscribed structures which may be similar to abscesses. A common soft tissue cyst is an epidermoid cyst, which is a subepidermoid nodule filled with keratin. In addition to physical exam clues which may help distinguish cysts from abscess, cysts are typically very well-circumscribed and more homogenous in appearance.
Figure 10. Epidermoid cyst (image courtesy of The Pocus Atlas and Dr. Robert Jones)
Soft tissue foreign bodies are a common pediatric presentation and can be easily identified on ultrasound. X-rays can be used to identify foreign bodies; however, their use is limited to radiopaque objects. On ultrasound, foreign bodies often appear as a hyperechoic defect.
Figure 11. Hyperechoic foreign body (glass) embedded in the soft tissue of a foot with posterior shadowing
Foreign bodies embedded for a prolonged time may have signs of infection, such as cellulitis or abscess (Figure 12).
Figure 12. Wooden splinter embedded in a patient’s plantar foot with surrounding fluid collection consistent with abscess
A foreign body’s composition can affect how it appears on ultrasound. Different materials can produce characteristic ultrasound artifacts.
| Foreign Body | Ultrasound Findings | Ultrasound Image |
|---|---|---|
| Wood | Hyperechoic with posterior shadowing |  |
| Glass | Hyperechoic with posterior shadowing May have comet tail artifact |   Images courtesy of Dr. Ashkon Shaahinfar |
| Metal | Very hyperechoic Often has a comet tail or reverberation artifact |  Image courtesy of The Pocus Atlas and Robert Jones DO, FACEP |
Ultrasound assistance in foreign body removal may be static (used to locate the foreign body’s position) or dynamic (using ultrasound to guide foreign body removal in real-time). Measuring the foreign body and assessing the object’s depth on ultrasound may assist in determining if bedside removal versus surgical removal is indicated.
Limited evidence suggests that there may be some sonographic differences between the papular urticaria of a “skeeter syndrome” and local cellulitis. On ultrasound, both findings will have thickening of dermal and subcutaneous tissues. Angioedema characteristically includes more linear, horizontal, striated bands — in comparison to cobblestoning found in cellulitis [1]. However, additional studies are needed to confirm this.
Figure 13. Ultrasound of angioedema (left) and cellulitis with cobblestoning (right). Angioedema image courtesy of Dr. Laura Malia.
Necrotizing fasciitis is a rare pediatric diagnosis but a rapidly progressive and life-threatening condition if not identified quickly. While necrotizing fasciitis is primarily a clinical diagnosis, imaging may be helpful when the diagnosis is uncertain. Computed tomography (CT) and magnetic resonance imaging (MRI) have good test characteristics; however, these tests are time-consuming and may not be available in all centers. CT also involves ionizing radiation. Point-of-care ultrasound has the benefit of rapid bedside use and lack of ionizing radiation.
On ultrasound, early necrotizing fasciitis presents with thickening of the subcutaneous tissue, similar to cellulitis. Fluid in the fascial layers may also be present, and a thick layer of pre-fascial fluid >4 mm has been associated with necrotizing fasciitis [2]. Subcutaneous air with dirty shadowing (Figure 14) is a characteristic but late finding in necrotizing fasciitis. These findings may be recalled using the “STAFF” mnemonic [3]:
Note: It may be difficult to distinguish early cases of necrotizing fasciitis from cellulitis. Therefore ultrasound should not be used to exclude necrotizing fasciitis. Patients with findings concerning for necrotizing fasciitis require additional work-up and surgical consultation.
Figure 14. Necrotizing fasciitis on POCUS exam showing the presence of air with dirty shadowing within soft tissue (image courtesy of Dr. Di Coneybeare)
For additional reading on ultrasounding necrotizing fasciitis, see these ALiEM articles:
There have been multiple studies (Table 3) that support the use of soft tissue POCUS for identification of cellulitis or abscess. Soft tissue POCUS has been shown to have good sensitivity and specificity. It has also been shown to be superior to clinical assessment in several pediatric studies.
POCUS can also reduce the length of stay (LOS) for our patients. In one pediatric study including 3,094 children suspected of a soft tissue infection who underwent either POCUS or radiology department ultrasound, POCUS was shown to have a shorter median LOS by 73 minutes (95% CI 52.4-93.6 min) [4].
| Study | N | Methods | POCUS Sensitivity (95% CI) | POCUS Specificity (95% CI) | Conclusions |
|---|---|---|---|---|---|
| Gottleib et al., Ann Emerg Med 2020 [5] | 2,656 | Systematic review of adult and pediatric studies | 94.6% (89.4-97.4%) | 85.4% (78.9-90.2%) | POCUS has good diagnostic accuracy. Led to correct change in management in 10% of cases. |
| Lam et al., J Emerg Med 2018 [6] | 327 | Prospective cohort study of children 6mo-18yrs comparing clinical assessment to POCUS | 90.3% (83.4-94.7%) | 80% (70.0-87.4%) | POCUS changed management in 22.9% of cases* |
| Subramaniam et al., Acad Emerg Med 2016 [7] | 800 | Systematic review of adult and pediatric (patients from birth – 21yrs) studies | 97% (94-98%) | 83% (75-88%) | POCUS may assist physicians in distinguishing cellulitis versus abscess. |
| Adams et al., J Pediatr 2015 [8] | 151 | Prospective cohort study of patients 3mo-21yrs comparing clinical assessment to POCUS | 96% (90-99%) | 87% (74-95%) | POCUS changed management in 27% of cases.** For every 4 ultrasounds performed, 1 correct change in management. |
| Sivitz et al., J Emerg Med 2009 [9] | 50 | Prospective cohort study of children <18yrs comparing clinical assessment to POCUS | 90% (77-100%) | 83% (70-97%) | POCUS changed management in 22% of cases. |
After reviewing the literature, you decide to perform a POCUS to evaluate for skin abscess. You place a linear, high-frequency transducer over the patient’s affected area and you observe the following:
The patient underwent successful incision and drainage of the abscess, and she was discharged home with antibiotics.
There has been a well-documented growth in the use of FOAM in graduate medical education [1-4]. The decentralized nature of FOAM along with concerns with the lack of peer review make the assessment of the quality of information difficult. Several years ago, a group of physicians set out to solve these problems by modifying the traditional systematic review format, and created the Systematic Online Academic Resource (SOAR) review. The SOAR review aims to “systematically identify online resources by topic…[and] assess the quality of these resources with a validated tool, and collate links.” [5]
Our review, “Systematic online academic resource (SOAR) review: Pediatric respiratory infectious disease,” [6] is the fourth in the AEM Education and Training series – and the first focusing on pediatrics. We identified 36 high-quality blog posts on this topic.
Previous SOAR reviews included the following:
| rMETRIQ Score | Topic | Blog/Podcast Post | Date of Publication |
|---|---|---|---|
| 20 | Epiglottitis | Radiopaedia: Epiglottitis | 1/29/10 |
| 19 | Strep pharyngitis | emDOCs Podcast – Episode 27: An Understated Myth? Strep Throat & Rheumatic Fever | 4/27/21 |
| 19 | Hand-foot-and-mouth disease | Radiopaedia: Enterovirus 71 | 1/24/14 |
Looking for a blog post on bronchiolitis? Pneumonia? Croup? Look no further! You can view these high-quality blog posts in our SOAR publication (subscription required) [6]. To make it easier, you can also identify these resources by topic on PEMBlog with Dr. Brad Sobolewski (coauthor of the SOAR review):
Using 177 search terms, our initial search yielded 44,897 resources, 441 of which met criteria for quality assessment.
| Renal | Endocrine | Sickle Cell | Pediatric Resp ID | |
|---|---|---|---|---|
| # Reviewed | 341 | 756 | 53 | 441 |
| High Quality | 34 (10%) | 121 (16%) | 8 (15%) | 36 (8%) |
| Poor Quality* | NA | NA | 11 (21%) | 67 (15%) |
* Poor quality was not assessed in the first 2 SOAR reviews
Special thanks to SOAR coauthors Brad Sobolewski, Cindy Roskind, Andrew Grock, JooYeon Jung, Shirley Bae, and Lisa Zhao.
