PE in children is relatively rare and its presentation differs from the typical presentation of an adult. The classic presenting symptoms of PE in adults such as dyspnea, pleuritic chest pain, cough, and hemoptysis are often absent in children and the PE may even be clinically silent (3). This may lead to a missed diagnosis of PE, especially in children who present with symptoms mimicking a secondary condition or if an embolism obstructs less than 50% of pulmonary circulation (5).Clinical decision tools with a high negative predictive value that are commonly used to rule out PE in adults such as the Wells' criteria, D-dimer, and The Pulmonary Embolism Rule-out Criteria tools have not been validated in pediatric populations, and pediatric-specific diagnostic risk prediction tools are lacking (6). Therefore, PE must be considered in children and adolescents presenting with unexplained respiratory signs/symptoms, no improvement despite appropriate management, and presence of prothrombotic risk factors.
Our patient had multiple risk factors for a hypercoagulable state given his diagnosis of ALL, pancytopenia, relative immobility, and recent treatment with PEG. Immobility, in addition to venous stasis and vascular injury, has been implicated as the main contributing factor in the formation of thrombosis in Virchow’s triad, and it was also thought to be a main factor in his development of his PE and penile pain. Although a decrease in oxygen saturation is a well-described effect of acute opioid administration, it is usually transient and should never hasten work-up for PE in an asymptomatic hypoxic patient with prothrombotic risk factors, such as our patient (7). Persistent desaturations two hours after morphine administration would be an unusual timeframe for morphine to induce desaturations. This patient was fortunate enough to be on a continuous oxygen monitoring, however, PE in children in the ED may be often missed due to the vague sequence of events leading to diagnosis, especially in asymptomatic patients at emergency departments where continuous pulse oximetry monitoring is not available. Although the etiology of this patient’s penile pain has not been fully ascertained, we suspect that the patient’s hypercoagulable state in the setting of ALL, immobility resulting in blood statis, and dehydration precipitated a transient thromboembolic event in his penile veins. His improvement in pain and decrease in swelling after heparin infusion initiation supports a hypothesis that his penile pain was caused by a thromboembolic event. US was obtained after heparin initiation. Furthermore, work up for a urethral stone was negative, further evidencing that the presenting symptom of penile pain in this patient was due to a thromboembolic phenomenon. Albeit rare, the differential diagnosis of acute penile pain in the ED should include priapism, urethral stone, infection, Mondor's disease, and acute worsening of chronic conditions such as sclerosing lymphangitis and Peyronie’s disease. Nephrolithiasis is a relatively uncommon problem in children presenting to the ED and the presentation in children differs significantly from in the adult population. Abdominal pain and hematuria are the most common, occurring in 53–75% and 14–33% respectively. The typical unilateral, colicky flank pain occurs in only about 7% of children. Because urinary tract infection (UTI) 8-45.9% of cases) and microhematuria (60–95% cases) are also relatively common, urinalysis should be performed in any child in whom nephrolithiasis is suspected (8–10). Other symptoms such as nausea, difficulty urinating, polyuria, dysuria, penile pain, or testicular pain can also be rarely present (11). Similarly, to adult patients with nephrolithiasis, the diagnostic superiority of computed tomography (CT) in children has been verified. Due to increased radiosensitivity of children compared to adults, the diagnostic advantages of CT must be considered against the substantial dose of radiation (12). Although urolithiasis cannot be ruled out based on normal urinalysis, x-ray and ultrasound, due to no associated symptoms/findings in our patient we decided not to pursue CT imagining.
Several new disease entities emerged during the COVID-19 pandemic. Hypercoagulability and severe inflammation in the setting of SARS-CoV-2 is known to increase the risk of thrombosis that can clinically manifest at various sites. Penile Mondor’s disease is a rare, generally self-limiting, thrombosis of the superficial dorsal vein that has been described in young and middle-aged men as well as recent SARS-CoV-2 positive patients with cardiovascular disease (13). It is a superficial dorsal vein thrombophlebitis of the penis manifesting as a visible painful cord located along the dorsal surface of the penis. In some cases, diffuse shaft swelling with associated signs of skin inflammation and intense pain have been described (14). The pathogenesis is not completely understood, and it is usually diagnosed through clinical signs and with Doppler ultrasound evaluation (13). Although our patient’s penile ultrasound was negative, the temporary nature of his swelling and pain in the setting of a hypercoagulable state indicate some overlapping features. He was not tested for SARS-CoV-2 during his ED admission, and it can only be speculated if acute COVID-19 infection contributed to his presentation. Albeit rare, priapism can be seen in patients who present to the ED with penile pain. It is a disorder in which the penis maintains a prolonged, rigid erection lasting longer than four hours unrelated to sexual interest. Several causes have been implicated including medications, sickle-cell anemia, cancer, trauma, foreign body, spinal injury and penile fibrosis. Although our patient would be predisposed to priapism given his ALL, the absence of erection on physical examination and no associated medications found upon review by a pharmacist, we effectively ruled-out priapism in this patient.
PE is an easily missed diagnosis among children who present to the ED and can be potentially fatal. A high index of suspicion is required in asymptomatic and oligo-symptomatic children with prothrombotic risk factors who develop thromboembolism-related symptoms at unusual sites and hypoxia in the ED setting (15).