Inguinal hernias are common in childhood with an incidence as high as 5%. Premature infants have an even higher incidence, and boys are approximately 10 times more likely than girls to develop an inguinal hernia. There are two types of inguinal hernias: indirect (common) and direct (rare). Indirect inguinal hernias result from failure of the processus vaginalis to obliterate toward the end of fetal development. With a patent processus vaginalis, the intra-abdominal viscera can protrude through the internal inguinal ring. Indirect inguinal hernias are more common on the right and present as a bulge in the groin by parental history or on physical examination. Maneuvers that increase intra-abdominal pressure, such as crying in an infant or blowing bubbles in an older child, may make the hernia easier to visualize. Associated symptoms such as vomiting, abdominal distention, constipation, blood in the stool, lethargy, or irritability suggest incarceration or strangulation of the hernia. Incarceration is most common in the 1st year of life. The differential diagnosis includes hydrocele, inguinal lymphadenopathy, testicular torsion, torsion of the appendix testis/epididymis, epididymitis/orchitis, and a retractile testicle.
Management and Disposition
With the history of scrotal swelling but a normal physical examination, refer to a pediatric surgeon for timely evaluation and repair. If a hernia is palpable, ensure that it can be easily reduced manually. Reduction of an incarcerated inguinal hernia may be facilitated by adequate pain control and sedation (80% successful). The reduction technique consists of gentle traction inferiorly on the hernia sac with pressure from above to straighten the inguinal canal. There is a high rate of early recurrence of incarceration. Admission to the hospital with repair in 24 to 48 hours after the associated edema has subsided is advisable. Immediate surgical consultation for operative repair is indicated for any incarcerated hernia that cannot be manually reduced.
Inguinal Hernia. (A) Right inguinal hernia in a male infant (B) Left inguinal hernia in a female infant. (Photo contributor: Lawrence B. Stack, MD.)
Transilluminate the scrotum. Hydroceles will transilluminate, whereas hernias will not.
The Trendelenburg position may aid in hernia reduction.
Palpate both testicles in the scrotum prior to diagnosing an inguinal hernia.
Plain abdominal radiographs are unlikely to be helpful in cases of scrotal swelling where the diagnosis is not apparent. Scrotal ultrasound has a diagnostic accuracy of over 90%.