(First of two parts)

THE scrotum is a pair of skin pouch or baglike structure that hangs beneath the male organ containing the testes and their accessory organs. The testes are suspended in the scrotum on each side by cordlike structures known as spermatic cord consisting of nerves, blood vessels and coiled ducts (epididymis) for storage, transmission and maturation of the sperm produced by the testes, the active participant in the process of procreation.

The testes manufacture the hormone testosterone responsible for the male characteristics and sex drive -- the macho thing.

Panagbenga 2009 blog

During pregnancy of a male baby, the fetal testes are located in the abdominal cavity until about the 32nd to 36th week of pregnancy, when they start to descend to the scrotum through the inguinal canals (pair of openings in the region of the groins that connect the abdominal cavity with the scrotum). The fetal inguinal canals normally close after the descent of the testes. Failure of the fetal inguinal canal to close may result in the protrusion of the intestine into the groin known as inguinal hernia or if the opening is large enough a part of the intestine may protrude down into the scrotum (scrotal hernia).

Failure of the testis to descend is known as cryptorchidism which maybe unilateral or bilateral. Bilateral cryptorchidism is a cause for concern as the testis cannot survive the higher temperature inside the abdominal cavity with resultant atrophy and eventual infertility (sterility). Another cause of concern is the reported higher incidence of testicular cancer in patients with cryptorchidism.

The function of the scrotum is to regulate the temperature of the testes. Production of sperm by the testes needs temperature lower than the temperature of the abdominal cavity. The scrotum regulates the heat through contraction or relaxation of the muscles of the scrotal wall. Warm environmental temperature relaxes the scrotal muscles enlarging the scrotum making the skin shiny. The opposite happens during cold weather. Scrotal muscles contracts reducing the size of the scrotum producing the characteristic skin corrugations.

The testicular temperature ranges from 33.6°C to 34.6°C or about 3°C lower than the rectal temperature. This is maintained even if the body temperature rises such as in fever. However, heat exposure of the scrotum like sauna bath will raise the testicular temperature about 1°C higher. Prolonged exposure may result in the lowering of sperm count causing infertility.

In children, scrotal temperature may become elevated in boys who wear plastic disposable diapers. Wearing of plastic diapers may raise testicular temperature to 1°C higher. It would be interesting to know later on the spermatogenesis status of these children. Fortunately, studies from Denmark have shown the wearing of disposable diapers do not predispose children to the development of testicular cancer. (J, Stockman, ed: Yearbook of Pediatrics, 2002 & 2004).

Scrotal swelling can affect males of any age, which can be acute (rapid onset, short duration) or chronic (gradual onset, long duration). Acute scrotal swelling is considered an emergency until proven otherwise as damage to the testis may be an urgent possibility. In this situation, the window of opportunity to save the testis by surgical intervention is only a matter of hours. Pain often accompanies acute scrotal swelling in contrast to chronic swelling, which is often painless. Swelling of the scrotum maybe unilateral or bilateral that may involve the scrotal wall (scrotal edema), its contents (enlargement of the testis, dilated blood vessels, etc.) or the accumulation of fluid (blood, pus, clear fluid).

The common cause of acute painful scrotal swelling is trauma to the testis occurring during play or sports. The pain may be mild or severe. The child may even lose consciousness. Severe injury may cause severe damage to the testis and results in marked swelling from edema and accumulation of blood. Urgent surgical evaluation and intervention should be undertaken to save the testis.

Torsion of the testis is the common cause of non-traumatic acute painful scrotal swelling. Torsion is the abnormal twisting of the testis in the scrotum that may compromise the blood supply and damage the testis. Torsion can occur at any age but are notably reported in pre-pubertal males from the rough and tumble play, sports and other forms of trauma in this age group.

Torsion of the testis presents as an acute onset of scrotal pain, swelling and redness. Scrotal pain often radiates to the abdomen associated with nausea and vomiting. Younger children may only present with unexplained episodes of crying and irritability. In this situation, it is essential to examine the scrotum. With torsion, the testis is swollen, diffusely tender and lying higher in the scrotum. Time is of the essence. Viability of the testis will depend upon the degree of torsion. Viability is not possible if the testis is completely twisted to compromise fully the blood supply of more than 6 hours. Torsion is a time-related surgical emergency. One should not rely on onset and duration of symptoms as a guide to the viability of the testis as it is not possible to determine clinically whether the twisting or torsion is complete or not. One should not delay in seeking expert advice and proceed immediately with the appropriate course of treatment to save the testis.

Orchitis is another cause of painful scrotal swelling. Orchitis is inflammation of the testis usually associated with inflammation of the epididymis (tubes connected to the testes that provide storage, transit and maturation of sperm). Inflammation may affect one or both testes and or epididymis. Epididymoorchitis are often caused by infection either bacterial or viral. Some viral infections are associated with pediatric contagious disease like mumps. Mumps orchitis is rare before puberty. In seventy percent of cases, only one testis is affected. Bilateral involvement may result in sterility.

The onset of swelling and tenderness in orchitis is not as acute as in torsion of the testis. As the inflammation spread to the rest of the testis and scrotal wall, the swelling and the pain will become prominent. Systemic-like symptoms maybe present such as chills, fever, lower abdominal pain, nausea and vomiting. Rectal pain and discomfort maybe the initial symptoms before the swelling, tenderness and redness of the scrotum. Kaplan G., Pediatrics in Review, Sept 2000. (To be concluded)