How Common is Lyme Disease Globally and in Urban Settings?

Patient Presentation
During her work commute, a pediatrician was listening to a podcast about the European outdoors. One of the segments discussed how Lyme disease was more common in urban areas of Europe than most people realized.
She saw many patients for concerns about tick bites and knew about the epidemiology in her location, but didn’t know as much about it in other locations.

Lyme disease (LD) is caused by several genospecies of Borrelia burgdorferi senu lato that are transmitted by ticks of the Ixodes ricinus complex. In the U.S. and Europe it is the most common vector-borne disease. It is named for Lyme, Connecticut in the 1970s when it was “discovered,” but there are reports of LD-type disease in Europe since 1883. There are 18 distinct genospecies with B. afzelii, B. garinii and B. burgdorferi sensu stricto being the 3 most common ones causing human infection. There are many species of Ixodes ticks but only 4 commonly bite humans. Ixodes ricinus mainly in Europe, I, persultcatus in Asia, I. scapularis in the eastern and central US, and I. pacificus in the western US and Canada. However I. pacificus is rarely infected and accounts for very few human infections.

I. scapularis lives for approximately 2 years and eats blood meals at each of its 3 stages, larval, nymph and adult. Ticks are not infected when they hatch from eggs (a single female can produce > 2000 larvae). They become infected from the blood they feed upon. For I. scapularis, reservoir hosts for larva and nymphs are small mammals (i.e. mice, shrews) and birds. Adults like larger mammals such as deer and dogs. (Dogs are used as sentinels for epidemiological studies of Borrelis sp. in the environment). Humans are dead-end hosts as the spirochetes are not sustainable in human tissues in large numbers. I. scapularis ticks need attachment to transmit LD (usually 36 hours or more). Therefore attachment prevention with long clothing, showering (within 2 hours of being outside) and tick checks have demonstrated decreased risks of ticks bites. Additionally, using insect repellents with 20-30% of DEET is recommended.

Nymph stages are particularly important in LD transmission as they are abundant and small. Nymphs tend to feed in the late spring/early summer seasons or similar time frame depending on the local global latitude. Nymph stages are sensitive to desiccation, therefore they are increased in areas of humidity.

A review of LD clinical symptoms can be found here. Serological testing for disease depends on the geography, especially the expected prevalence of the organism. “In general, serological testing is only considered useful when the prior probability of disease is between 20% and 80%. In circumstances when the risk is lower, positive laboratory tests are more likely to reflect a false-positive result than actual infection.” Therefore management decisions about testing, prophylactic antibiotic use or treatment antibiotic use depends on location.

Learning Point
LD is seen around the northern hemisphere of the world but is particularly common in Northeastern, Mid-atlantic and upper Midwest areas of the US and corresponding Canadian provinces with I. scapularis as the primary vector. Western coastal areas including British Columbia and Northeastern Mexico and the Baja, have I. pacificus ticks but the number of human cases of LD is few. In Europe LD common in all Eastern, Central and Western European countries below 1300 m2 elevation and the primary vector is I. ricinus. B. afzelii is more predominant in Northern and Eastern Europe “(e.g. Scandinavia, Baltic states, Czech Republic, Slovakia, Croatia, Bulgaria).” B. garinii is more predominant in Western Countries “(eg. Austria, Switzerland, United Kingdom).”

LD can also be seen in the northern Africa coast in northern Algeria, Morocco and Tunisia with the common species being B. lusitaniae. LD is seen in Turkey and Russia with extension into the Asian continent including Japan, Korea, Taiwan and China. There are possibly LD cases noted in the southern hemisphere in Australia, Brazil and South Africa.

In the United Kingdom, Scotland has the highest prevalence rate along with South West and Southern England. Birds are a more important vector in Europe and it is thought that this is part of the reason that Scotland and other countries with large coastlines such as Norway may have higher disease rates. Ground feeding birds, especially thrushes, carry the most ticks and therefore potentially Borrelia sp.

Studies have found ticks with I. ricinus in urban areas throughout Europe including 2 South London parks. Urban greenspaces are often not thought of as carrying ticks and other potential environmental hazards, but can. This is especially true for green spaces at the “edge” of the city (periurban) or with increased connectivity between the green spaces which helps to support the birds, mammals and other environments suitable for ticks to survive and migrate between. Even isolated pockets of green space can harbor significant urban tick populations. The green space microclimate is also important with more trees, bushes and leaf-litter supporting a more humid environment which supports tick populations, while increased gravel or paved landscapes are drier and do not support tick populations as well.

Questions for Further Discussion
1. Describe erythema marginatum?
2. What is the local prevalance of Borrelia sp. in your location?
3. What is the treatment for Lyme neuroborreliosis in children?

Related Cases

    Symptom/Presentation: None
    Age: None

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for these topics: Lyme Disease and Tick Bites.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Cairns V, Wallenhorst C, Rietbrock S, Martinez C. Incidence of Lyme disease in the UK: A population-based cohort study. BMJ Open. 2019;9(8):e025916. doi:10.1136/bmjopen-2018-025916

Mead PS. Epidemiology of Lyme disease. Infect Dis Clin North Am. 2015;29(2):187-210. doi:10.1016/j.idc.2015.02.010

Heylen D, Lasters R, Adriaensen F, Fonville M, Sprong H, Matthysen E. Ticks and tick-borne diseases in the city: Role of landscape connectivity and green space characteristics in a metropolitan area. Sci Total Environ. 2019;670:941-949. doi:10.1016/j.scitotenv.2019.03.235

Rizzoli A, Silaghi C, Obiegala A, et al. Ixodes ricinus and Its Transmitted Pathogens in Urban and Peri-Urban Areas in Europe: New Hazards and Relevance for Public Health. Front Public Health. 2014;2:251. doi:10.3389/fpubh.2014.00251

Oechslin CP, Heutschi D, Lenz N, et al. Prevalence of tick-borne pathogens in questing Ixodes ricinus ticks in urban and suburban areas of Switzerland. Parasit Vectors. 2017;10(1):558. doi:10.1186/s13071-017-2500-2

Nelson C, Banks S, Jeffries CL, Walker T, Logan JG. Tick abundances in South London parks and the potential risk for Lyme borreliosis to the general public. Med Vet Entomol. 2015;29(4):448-452. doi:10.1111/mve.12137

Hansford KM, Fonville M, Gillingham EL, et al. Ticks and Borrelia in urban and peri-urban green space habitats in a city in southern England. Ticks Tick-Borne Dis. 2017;8(3):353-361. doi:10.1016/j.ttbdis.2016.12.009

Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa

Can Radiolucent Foreign Bodies Be Identified?

Patient Presentation
A 30 month-old female came to clinic with a history of a cough for 2-3 weeks with rhinorrhea. Her mother was concerned because the day before she had an unwitnessed choking episode where the mother heard what she thought was choking but had stopped when she entered the room. The child was eating crackers at the time. The mother did not see any missing toys or toy parts in the room and the child could not answer if she had swallowed something or put something in her mouth. The mother was quite adamant that she wanted a chest x-ray because she had read on the Internet that aspiration could be diagnosed this way. She had been eating and drinking well since the episode and had no fever. The past medical history was positive for mild intermittent asthma but the mother had not been giving albuterol as it didn’t appear to be helping with this episode.

The pertinent physical exam showed a child with no respiratory distress with normal vital signs, growth parameters and an oxygen saturation of 98%. HEENT showed copious rhinorrhea with some clear fluid behind her tympanic membranes without erythema. Her lungs were difficult to auscultate because she became very fussy and didn’t want to be examined. The rest of her examination was negative.

The diagnosis of a viral syndrome in a setting of previous bronchospasm was made. The resident physician was explaining his findings to the mother who was not very happy with the diagnosis. She then stated, “I think now that she swallowed a toy piece and a want chest x-ray. Besides she’s been coughing for 2 weeks now.” The attending physician also tried to listen to the child who again refused to be examined and the mother became more vocal that she was “sure she had swallowed a toy piece.” The physicians discussed that chest x-rays were not fool-proof for diagnosing foreign bodies. The mother was adamant and the physicians acquiesced. A radiologic evaluation of a chest radiograph was done and was normal. The mother became much less agitated, and verbalized that she was now okay, “because she doesn’t have something in her lungs.”

Foreign bodies are common problems for young children particularly ages 2-4 years who will mouth many objects and aspirate or swallow them. Children will also place foreign objects in other body orifices such as ears or noses. It is also not uncommon that young girls will inadvertently have toilet paper caught in the vaginal area during hygiene. Many of these foreign bodies may work their way out naturally not causing any problems, or may come to attention later because of chronic problems such as a foul-smell or discharge. Older children may tell adults that they have placed a foreign body in an orifice and thus have it come to attention.

Because mouthing food and non-food objects is common in young children, it is not uncommon that the children will cough or choke. Usually this expels the objects and fixes the problem. Parents may not even notice the episode as coughing and choking in general occurs frequently in young children. Some children will have more significant problems if the objects lodges in the airway or at particular points in the gastrointestinal tract, and therefore have continued symptoms and come to medical attention. For example, in a 2013 retrospective review of patients who underwent bronchoscopy for suspected radiolucent foreign body aspiration, most were witnessed events (81%) in a ~2.6 year old (average age), who continued to have problems with wheezing (64%), coughing (43%), choking (39%), stridor (6%) or lethargy (0.7%). Bronchoscopy found a radiolucent foreign body in 93% of the cases which included food (68%), plastic (18%), rock (3%) or unidentifiable object (11%).

Learning Point
For unwitnessed events or when a child admits to the event, radiographs may be used to try to identify the object and location. A radioopaque object is usually easy to identify, and a mnemonic of common radiolucent objects can be found here. A radiolucent object is harder. On chest radiograph (CXR) a radiolucent object in the bronchial tree may show decreased aeration, air trapping or even lung collapse. Often the CXR is normal, which also does not exclude a foreign body. Other methods include visualization with ultrasound, computed tomography, magnetic resonance imaging and even handheld metal scanners. All of these modalities their pros and cons. Some require radiation, are expensive, require a skilled technologist or are very limited to the types of objects that can be identified.

Many, but certainly not all, radiolucent objects can be identified using plain radiographs. In a 2014 study, common radiolucent objects were placed along with control objects in a gelatin slab that was then encased in a water equivalent phantom depicting a child. A plain radiograph was taken and blinded radiologists reviewed the radiograph. Each radiologist correctly identified most of the objects (avg. 8 of 14). 4 objects were not identified by any radiologist. Objects identified were a plastic army figure, lump of clay, crayon, eraser, glass diamond bead, paperclip, drywall anchor, and ring. Items not identified were a plastic barrette, plastic beads and a Lego® brick. The radiologists also were able to identify where some other objects were placed on the radiograph but were unable to identify the specific object. Images of the objects in the study can be found here.

Questions for Further Discussion
1. How would you have handled the adamant parent situation described above?
2. Where do most gastrointestinal or respiratory tract foreign bodies lodge?
3. What types of foreign bodies can be monitored and what need to be removed because of their intrinsic properties?
4. What are some techniques for foreign body removal?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for these topics: Foreign Bodies and Cough.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Saps M, Rosen JM, Ecanow J. X-ray detection of ingested non-metallic foreign bodies. World J Clin Pediatr. 2014;3(2):14-18. doi:10.5409/wjcp.v3.i2.14

Mortellaro VE, Iqbal C, Fu R, Curtis H, Fike FB, St Peter SD. Predictors of radiolucent foreign body aspiration. J Pediatr Surg. 2013;48(9):1867-1870. doi:10.1016/j.jpedsurg.2013.03.050

Behera G, Tripathy N, Maru YK, Mundra RK, Gupta Y, Lodha M. Role of virtual bronchoscopy in children with a vegetable foreign body in the tracheobronchial tree. J Laryngol Otol. 2014;128(12):1078-1083. doi:10.1017/S0022215114002837

Hamzah HB, James V, Manickam S, Ganapathy S. Handheld Metal Detector for Metallic Foreign Body Ingestion in Pediatric Emergency. Indian J Pediatr. 2018;85(8):618-624. doi:10.1007/s12098-017-2552-5

What Affects the Nutritional Quality of Plant-Based Milk Substitutes?

Patient Presentation
A 12-month-old female came to clinic with her mother for her health supervision visit. The infant was breastfeeding and had a history of cow’s milk protein and soy allergies where the patient had bloody stools or hives. The family was vegetarian but ate some dairy products and eggs. She asked about using a pea-based milk substitute to wean the infant. The family had tried eggs and peanut products without any problems for the infant. They also had tried some yogurt and felt her stools were much looser but there was no obvious blood in them. The infant ate age-appropriate complimentary foods without difficulty. The past medical history was otherwise negative.

The pertinent physical exam showed a healthy female with weight in the 25-50% and height and head circumference in the 50-75%.
Her physical examination was normal.

The diagnosis of a healthy female with food allergy or sensitivities was made.
The pediatrician knew that there could be problems with plant-based milk substitutes for young children including protein and other nutrient insufficiencies depending on the product used.
“Let me do a little research and talk with the hospital dietician who works in our gastroenterology clinic. I’ll get back to you in a few days but in the meantime, just continue the formula,” he answered.

People today may be eating more plant-based products because of:

  • Allergen avoidance – lactose or cow’s milk allergy, 14% of people with cow’s milk allergy will also have soy allergy.
  • Cultural importance
  • Contamination avoidance e.g. growth hormone or antibiotic residues in cow’s milk production
  • Specific diseases, e.g. cholesterol/lipid issues
  • Environmental impact
  • Ethical or religious considerations
  • Improved nutrition

With population growth “[t]he demand for food is expected to grow by 70% until 2050….While the expected protein consumption is believed to grow by 80%.” Protein sources are also expected to come from more resource intense foods.

Plant-based milk substitutes (PBMS) look like cow’s milk but are water-based extracts of legumes, oil seeds and nuts, cereal or pseudocereals. Soy milk and other soy products are the most common globally.

Common commercial plants utilized include:

  • Soy
  • Almond
  • Coconut
  • Hemp
  • Kamut
  • Oat
  • Maize
  • Millet
  • Peanut
  • Quinoa
  • Rice
  • Rye
  • Sesame
  • Sorghum
  • Tiger-nut (actually a tuber) – used to make Horchata
  • Wheat

Some plant-based drink examples include:

  • Amazake – rice, from Japan
  • Atole, maize, from Mexico
  • Boza – wheat, rye, millet, maize, common in south eastern Europe
  • Bushera – sorghum or millet, from Uganda
  • Chicha – grains and fruits, common in the Andes mountains
  • Horchata or tiger-nut milk, from Spain
  • Sikhye – rice, malt and sugar from South Korea
  • Soy milk – soy, from Asia especially China

The basic PBMS production process involves:

  • Taking the plant, adding water and grinding into a slurry- the plant can have water added first then is wet-milled, or is dry-milled then water is added to the resulting flour
  • Separating the solid wastes by filtration, decanting, centrifugation, etc.
  • Product formulation including other treatments such as fermenting or adding oil, flavoring, sugars, stabilizers and nutritional fortifiers
  • Homogenization to keep the product in the water suspension otherwise the particles can separate out as these are emulsions or colloidal suspensions
  • Pasteurization or ultra high temperature treatment to prevent microbial contamination
  • Packaging

Product formulations are affected by many things including temperature, pH, treatment duration, and when in the process the treatment is done. These make various nutrients more or less available (especially protein and fat) and with different qualities (i.e. textures, tastes, that make the end product more desirable to consume and nutritionally preferable). Fermentation, using bacteria, fungi or yeasts, is often used to improve nutrition, taste, and shelf life.

Additions to the basic product are exceptionally diverse because of the diverse products being made. Stabilizers prevent product degradation and nutritional supplements may be needed because naturally occurring water-soluble vitamins and other nutrients were destroyed or lost in the processing. Even different calcium types, added to fortify the product and to stabilize it, and make the calcium partially or wholy bioavailable. Calcium is less bioavailable if calcium triphosphate is used but is 100% bioavailable if calcium carbonate is used. Additions can also include animal ingredients.

Consumers often expect PBMS or other plant products to taste like cow’s milk or animal products when they are not. Some consumers complain of a chalky or pasty feel or of a beany taste. “[A] good approach…would be to appreciate the taste of the plant ingredients.” Producers are trying to make products that are nutritious, tasty and affordable for consumers.

High quality data is limited to determine the impact of protein products on the environment but they may have an improved impact utilizing less land but the issue is complex. For example, almonds are a good source of PBMS. Almonds are grown mainly in California (80%) and they require a great deal of amount of water which is limited. They also do not wind-pollinate well and therefore require bees for pollination and unfortunately the bee populations are also dwindling. Environmental contaminants can also occur in plant-based products and not solely in animal based products.

Learning Point
“In reality the nutritional properties [of plant products] vary greatly, as they depend strongly on the raw material, processing, fortification, and the presence of other ingredients such as sweeteners and oil.”

In general however, plant-based products have:

  • Lower protein and the protein is of lower quality – the protein may be of lower quality because of limiting amino acids (legumes = methionine, cereals = lysine) however again it depends on the actual product.
  • Lower cholesterol and improved lipid profile
  • Calories are about the same as skin milk
  • May have lower calcium, iodine, iron, phosphorus, vitamin B12, riboflavin, zinc, etc.
  • More or less allergens

PBMS are often lower in protein and young children are potentially at risk for protein malnutrition if PBMS are used without an understanding of the differences between animal milk and PBMS. Not only protein may be insufficient for infants but other vitamins and minerals may be insufficient. Some PBMS do have higher protein levels such as peanut or cowpea products, but again it depends on the actual product.

Questions for Further Discussion
1. What types of foods should vegetarians eat to maintain their nutrition? A review can be found here
2. How much protein does someone need to eat? A review can be found here
3. What are indications for consultation with a dietician?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for these topics: Vegetarian Diet and Nutrition.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Jeske S, Zannini E, Arendt EK. Past, present and future: The strength of plant-based dairy substitutes based on gluten-free raw materials. Food Res Int Ott Ont. 2018;110:42-51.

Makinen OE, Wanhalinna V, Zannini E, Arendt EK. Foods for Special Dietary Needs: Non-dairy Plant-based Milk Substitutes and Fermented Dairy-type Products. Crit Rev Food Sci Nutr. 2016;56(3):339-349.

Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa

What Are Pulmonary Embolism Risk Factors?

Patient Presentation
A 17-year-old female came to clinic for followup of pneumonia that had been diagnosed when she was on vacation 1 week previously. She had been coughing for a couple of days, and the cough was worsening. She developed some shortness of breath and right-sided chest pain, so her parents took her to the local emergency room. “In the emergency room, they thought I might have a blood clot, so I had to have a CAT scan that they said was normal. They gave me medicine in my arm which helped with the chest pain and then gave me some pills for the pain. I took them for a couple of nights to sleep but stopped after that. I’m also almost done with the antibiotic they gave me,” she explained. Her mother said that the doctors were worried about the blood clot because the patient was using birth control pills for dysmenorrhea and the patient’s maternal aunt had had a blood clot that went to her lung. “She found out a few months ago that its a blood problem. I don’t know exactly what it is but my sister is supposed to let me know. I guess we haven’t told you that yet so you don’t know. It’s new in our family,” described the mother. The teenager said, “I’m doing a lot better now with a lot less coughing but some is still there. The pain has gone away.”

The pertinent physical exam showed normal growth parameters and vital signs with a respiratory rate of 18 per minute and an oxygen saturation of 99%. HEENT revealed some minor rhinorrhea with a small amount of serous fluid in her ears bilaterally. Her lung examination still had slightly decreased breath sounds on the right but no obvious crackles. Chest pain could not be provoked.

The diagnosis of right lower lobe pneumonia that was resolving was made. The physician recommended that the mother find out what the cause of the aunt’s blood clot was so that the family members could be evaluated if necessary. He also noted the information in the medical record.

Pulmonary embolism (PE) is potentially life-threatening but fortunately rare event especially in the pediatric population. It was first described in children in 1861. PE is likely underreported because of minimal or non-specific clinical symptoms. The incidence is estimated at 0.05-4.2% with the 4.2% based on autopsy reports. It is probably also increasing as more central venous catheters (CVC) are used, and more children are surviving previously poor prognostic diseases. There is a bimodal distribution with cases < 1 year (especially neonates which account for ~50% of this group) and in teenagers. Neonates appear to have a high rate because of increases in CVC use and teenagers risks are felt to be increased with oral contraceptive use. Oral contraceptives alone are rarely felt to be solely responsible for PE though. Recurrence rate is 7-18% and death with PE is ~10% with the main cause being the patient's underlying medical condition.

Venous thrombosis can occur when there is injury to a vessel wall, venous stasis and hypercoagubility. Pulmonary embolism occurs when the thrombus is dislodged, moving through the blood vessels, through the right side of the heart and lodges in the pulmonary arterial system. Patients may have no symptoms if the thrombus involves less than 40-50% of the pulmonary circulation. Through various mechanisms, PE can cause hypoxia, hemodynamic instability and cardiopulmonary collapse. Massive PE where the pulmonary blood flow is occluded to the point of hemodynamic instability is rare in children. Massive PE can present with dyspnea, hypoxemia, hypotension, syncope, right-sided heart failure and sudden death.

Classically, PE presents with shortness of breath, chest pain and hemoptysis. These symptoms only occur in some patients. Deep venous thrombosis (DVT) symptoms of a painful extremity can also occur. In children, upper extremity DVTs are more common than in adults as more upper extremity CVCs are used in children. Unexplained tachypnea may be another non-specific finding that points towards PE. Pleuritic chest pain, shortness of breath and cough were more likely to be found in children evaluated for PE.

PE is rare so the differential diagnosis includes more common disease processes such as pneumonia, atelectasis, pneumothorax, and empyema. Congenital abnormalities and malignancies also need to be considered in the proper circumstances.

The diagnosis of PE can be difficult as noted. D-dimer testing is a sensitive screening test for adults, but can be normal in many children (15-40%) with known PE. Electrocardiogram with right-sided cardiac changes may be seen but again are less common in children. Arterial blood gas can show hypoxemia, hypercapnea and respiratory alkalosis. Echocardiogram can be helpful in some children particularly those with known congenital heart disease. Chest radiographs are frequently normal but can show hypovascularity in affected areas, wedge-shaped densities or a prominent central pulmonary artery. Computer tomography-pulmonary angiography is the primary imaging modality for PE diagnosis but other types of imaging may be used such as magnetic resonance imaging.

Treatment is usually with anticoagulants, potential thrombectomy or thrombolysis, and treatment of any underlying cause identified. Prevention includes ambulation and movement, adequate hydration, anticoagulants (usually for a period of time only), and inferior vena cava filters.

Learning Point
PE usually occurs in children with known risk factors with up to 80-96% having an identifiable problem, whereas in adults up to 30% are idiopathic.

Risk factors for PE in children include:

  • Congenital heart disease
  • Central venous catheters
  • Deep venous thrombosis – current or previous
  • Hypercoagulable states including malignancies, nephrotic syndrome and sickle cell disease
  • Immobilization
  • Obesity
  • Medications including oral contraceptives or other estrogen use
  • Prothrombic states including anti-phospholipid antibodies, Factor V Leiden, Protein C, and Protein S
  • Pulmonary embolism – previous
  • Recent surgeries
  • Trauma

Questions for Further Discussion
1. What are causes of sudden death in children? A review can be found here
2. What are causes of wheezing? A review can be found here
3. What are causes of chest pain? A review can be found here

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Pulmonary Embolism

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Navanandan N, Stein J, Mistry RD. Pulmonary Embolism in Children. Pediatr Emerg Care. 2019;35(2):143-151. doi:10.1097/PEC.0000000000001730

Ramiz S, Rajpurkar M. Pulmonary Embolism in Children. Pediatr Clin North Am. 2018;65(3):495-507. doi:10.1016/j.pcl.2018.02.002

Ignjatovic V. Paediatric pulmonary embolism: a pathway to improved outcomes. Lancet Haematol. 2019;6(3):e115-e116. doi:10.1016/S2352-3026(19)30012-2

Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa