A 6-year-old boy from Japan presented to the pediatric emergency department with sudden onset of abdominal colic and repeated episodes of bilious vomiting. He had a recent travel history to the Philippines, a region with high prevalence of Ascaris lumbricoides infection. On examination, he appeared pale but showed no signs of dehydration, abdominal distension, tenderness, or palpable mass. Vital signs were stable except for a mild fever of 38.0°C. Laboratory tests revealed mild leukocytosis (14,400/µL) and elevated C-reactive protein (1.29 mg/dL), suggesting a low-grade inflammatory response. Stool testing for rotavirus, adenovirus, and norovirus was negative, and culture showed normal flora.
Abdominal ultrasound was performed urgently due to concern for intestinal obstruction. The scan revealed multiple round, concentric structures within the small intestine with a central hypoechoic core surrounded by hyperechoic rings—classic “target” or “bull’s eye” appearance consistent with Ascaris worms. In longitudinal view, a tubular structure with two parallel hyperechoic lines separated by a hypoechoic center was identified, resembling a “railway track” or “3-line sign.” These findings are highly specific for live parasitic infestation. Notably, there was no evidence of bowel wall thickening, fluid accumulation, or dilatation, which ruled out mechanical obstruction or inflammation. Color Doppler imaging confirmed absence of blood flow within the tubular structure, further supporting the presence of a non-vascular foreign body.Scutellarin Data Sheet
Despite resolution of clinical symptoms the following day, the sonographic abnormalities persisted, prompting further investigation. Capsule endoscopy confirmed a single moving worm in the jejunum, measuring at least 10 cm in length. After treatment with pyrantel pamoate, a 20-cm-long worm was expelled, confirming the diagnosis of intestinal ascariasis.
This case illustrates the diagnostic utility of ultrasound in identifying pediatric intestinal ascariasis, particularly in developed countries where the condition is rare. Ultrasound is rapid, safe, non-invasive, and widely available, making it ideal for initial evaluation in emergency settings. Key sonographic features include:
– Target-like appearance on transverse scans: caused by the worm’s internal structure with a central core and surrounding hyperechoic layers.
– Parallel echogenic lines on longitudinal scans: representing the outer cuticle and inner intestinal wall.
– Characteristic slow, pendular, non-directional movement of the worm, visible during real-time imaging.
– Absence of Doppler signal within the worm, distinguishing it from vascular structures.
These features help differentiate Ascaris from other causes of intestinal masses such as lymphadenopathy, tumors, or fecal impaction. However, challenges remain: poor visualization may occur if worms are mixed with feces, if intestinal gas interferes, or if the patient cannot remain still. In children, motion artifacts can reduce image quality, and clinicians must maintain a high index of suspicion when evaluating unexplained abdominal pain or bilious vomiting.2,4-Dichlorothieno[3,2-d]pyrimidine site
In conclusion, ultrasound plays a pivotal role in the early detection of pediatric intestinal ascariasis.PMID:34799087 Its ability to identify characteristic imaging patterns enables prompt diagnosis and treatment, avoiding unnecessary invasive procedures. Emergency physicians should be familiar with these sonographic signs, especially in children with travel history to endemic areas. Early recognition not only improves patient outcomes but also reduces healthcare burden by preventing misdiagnosis and overuse of advanced imaging. Ultrasound remains the cornerstone of non-invasive evaluation for suspected parasitic intestinal disease in children.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com