Chapter XIII.11. Acute Scrotum
Daniel M. Bender, MA
Robert G. Carlile, MD
August 2022

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A 12 year old male presents to the E.D. at 4 a.m. with a chief complaint of acute onset of severe left scrotal pain with onset 3 hours earlier (1 a.m.), which awoke him from sleep. The pain is constant and does not change with position. There is no history of trauma. He has no dysuria, fever, chills, nausea, or vomiting. The triage nurse pages the ultrasound technician on call for a stat ultrasound.

Exam: He is afebrile, but in moderate distress secondary to left scrotal pain. The left hemiscrotum is mildly edematous, firm, and slightly erythematous. The left testicle has a high transverse lie in the left hemiscrotum, with marked tenderness to palpation. The cremasteric reflex is absent on the left. The right hemiscrotum and testicle are normal on exam. The circumcised penis is normal, with no urethral discharge present. No inguinal hernias are present.

An emergent urological consultation is obtained since a clinical diagnosis of testicular torsion is highly suspected. The urologist is advised that the ultrasound technician has already been paged. He agrees to arrive at the hospital soon. An IV is started and the patient is given IV acetaminophen to control his pain. There is no immediate reply from the ultrasound technician. A point of care ultrasound (POCUS) is done by the emergency physician which shows very different Doppler flow patterns comparing the right and left sides with poor perfusion on the left. The ultrasound technician arrives in the E.D. Mobile phone problems prevented the technician from calling the E.D. The ultrasound technician confirms the absence of blood flow in the left testicle. The urologist and anesthesiologist arrive in the E.D. Consents for surgery and anesthesia are obtained. A urinalysis is normal.

The patient is transferred to the operating room. Scrotal exploration, under anesthesia, reveals a 720-degree torsion of the left spermatic cord, an ischemic testicle, and a bell-clapper deformity. With detorsion, the left testicleís normal color returns. The left testicle is then fixed to the scrotal wall to prevent retorsion. The right testicle is also fixed to the scrotal wall. Postoperatively, his pain is markedly relieved with detorsion of the left testicle, and the remainder of his recovery is unremarkable.

The acute scrotum is a urologic emergency characterized by a sudden, painful swelling of the scrotum or its contents. The differential is broad and includes testicular torsion, epididymitis, orchitis, trauma, inguinal hernia, acute infection, and vasculitis. Of these select conditions, it is important to rule out testicular torsion immediately, since this is a true surgical emergency. The time window to salvage a torsed, ischemic testicle is short. The intraoperative testicular salvage rate approaches 100% if detorsion is performed within 6 hours of the start of the pain, but decreases to 50% and 10% at 12 and 24 hours, respectively (1). Despite intraoperative salvageability, long-term outcomes for even a 6 hour or 10 hour delay to treatment show 56% and 100% testicular loss rates, respectively (2). Therefore, acute scrotal swelling should be considered testicular torsion until proven otherwise.

Testicular torsion occurs most commonly during puberty, with the newborn period being the second most common. In males younger than 25 years, the incidence rate is 1 in 4000 (1). The inciting event for testicular torsion remains a mystery. Proposed hypotheses include the onset of rapid testicular growth at puberty and temperature changes activating the cremasteric reflex. Interestingly, sleep onset is positively associated with testicular torsion, suggesting a relationship with lower ambient temperatures (3).

Testicular torsion can be classified as either extravaginal or intravaginal, depending on the relationship of the tunica vaginalis to the area of the spermatic cord that twists (see Figure 1). The tunica vaginalis is a membrane consisting of two layers, one of which covers the testes and the other of which reflects onto the scrotum, covering its inner surface. This double membrane anchors the testicle within the scrotum and creates a potential space around the testes.

Figure 1. Diagramatic representation of testicular torsion associated anatomy. Normal anatomy (A). Note that the difference between extravaginal (B) and intravaginal (C) testicular torsion is whether the spermatic cord twists outside of or within the tunica vaginalis (shown in blue in the diagram). The normal testicle (A) is attached to the spermatic cord resembling the letter "b" or "d", while the bell-clapper deformity (D) has a testicle with a horizontal lie.

Intravaginal torsions account for 90% of all testicular torsions and occur when the testes rotate freely on the spermatic cord within the potential space of the tunica vaginalis (4). Approximately 12% of males have an inappropriately high attachment of the tunica vaginalis on the spermatic cord, which further increases the risk of an intravaginal torsion (1). This is called the bell-clapper deformity because the testicle lies horizontally and resembles an oval hanging from a swinging rod resembling the clapper (the ringer) in a bell. This is in contrast to the normal testicle, which resembles the letter "b" or "d" with the testicle positioned vertically attached to the cord on its side. Bell-clapper deformities are commonly bilateral, placing the contralateral testicle at risk for torsion (1).

Extravaginal torsions occur perinatally during testicular descent and prior to testicular fixation in the scrotum (4). The incomplete fixation of the gubernaculum (the cord extending from the fetal testis to the fetal scrotum which occupies the potential inguinal canal and guides the testis in its descent) to the scrotal wall allows the entire testis and tunica vaginalis to freely rotate within the scrotum (5). The rotation of the cord is "extravaginal" because it occurs proximal to the attachment of the tunica vaginalis which encloses the testes, and both the spermatic cord and the tunica vaginalis torse. Extravaginal torsions comprise less than 10% of all testicular torsions (4).

The sudden onset of severe testicular pain, sometimes with associated nausea and vomiting, is suggestive of testicular torsion, especially in the adolescent. Fever and dysuria are not commonly reported in testicular torsion. Intermittent testicular torsion should be suspected when brief episodes of acute testicular pain occur periodically. Torsion of the testicular or epididymal appendage (appendix testis or appendix epididymis) may also result in a similar constellation of symptoms. Compared to testicular torsion, appendage torsion usually presents in mid-childhood with mild focal tenderness and generally lacks systemic findings such as nausea or vomiting (6).

Epididymitis and orchitis, on the other hand, are typically associated with fever, dysuria, and a more gradual onset of scrotal pain, usually over several days. Risk factors for the development of epididymitis in children include anatomic urogenital abnormalities that predispose to urinary tract infections and reflux of urine. These include urethral strictures, posterior urethral valves, myelodysplasia with neurogenic bladder, severe hypospadias, and an ectopic ureter (7). Inflammation of the epididymis and testes may also occur secondary to viral infections. A child complaining of fever and parotid gland swelling in addition to scrotal pain is highly suggestive of mumps orchitis, the most common known cause of viral orchitis (6).

Inguinal hernia, hydrocele, vasculitis, and trauma may also present as an acute scrotum. A recent history of any condition resulting in increased intraabdominal pressure, such as constipation or upper respiratory infection, may point to an inguinal hernia or hydrocele. Henoch-Schonlein purpura (HSP) is a vasculitis that usually presents with purpuric rash, arthritis, nausea, vomiting, and occasionally with acute scrotal swelling. The scrotal swelling is usually bilateral (5). Trauma, no matter how minor, may be a cause of testicular pain and should be sought in the history (e.g., straddle injury, wrestling, sports). Although a history of trauma may suggest a traumatic etiology of pain and swelling, this does not rule out the presence of testicular torsion.

The physical exam should be performed in conjunction with the history. While some information can be derived from the patientís level of distress, vital signs, and abdominal exam, direct examination of the penis and scrotum is necessary. The presence or absence of inguinal and scrotal swelling, urethral discharge, lacerations, ecchymoses, or rashes should be noted, along with a description of the testes and any areas of pain or tenderness. The cremasteric reflex is sometimes useful in distinguishing testicular torsion from epididymitis. Gently stroking the medial thigh elicits reflexive contraction of the cremasteric muscle and results in ipsilateral testicular movement. An absent cremasteric reflex, in conjunction with testicular tenderness, is commonly associated with testicular torsion (8). This is in contrast to epididymitis where the cremasteric reflex is usually present.

Testicular torsion should be considered the leading diagnosis of acute scrotal pain until it can be definitively ruled out. The combination of sudden-onset, severe unilateral testicular pain, tenderness, absent cremasteric reflex, and no reduction in pain on testicular elevation (negative Prehnís sign) highly suggests testicular torsion. The torsed testicle may also appear more cephalad than normal due to the spermatic cord twisting on itself. It is not uncommon for a torsed testicle to lie transversely, especially in the case of a bell-clapper deformity. These positional changes are not seen in epididymitis or orchitis.

Differentiating the testicle from the epididymis on palpation can also help distinguish between testicular torsion, epididymitis, and testicular appendage torsion. In testicular torsion, the affected testicle and epididymis (if palpable) are exquisitely tender. In epididymitis, the testicle itself is not tender, but the epididymis is palpable and tender. Epididymitis has a more gradual onset, with notable tenderness. A cremasteric reflex is usually present, and the pain may be relieved with testicular elevation. Fever, pyuria, and dysuria may be present (7).

Torsion of a testicular appendage may present similarly to an acute testicular torsion. Characteristic features of an appendix torsion include localized tenderness of the upper part of the testes and a "blue dot" sign in the overlying scrotal skin due to venous congestion of the torsed appendage.

Color Doppler ultrasound has great utility in differentiating between scrotal pathology and ruling out testicular torsion in equivocal presentations (8). Doppler ultrasound is preferred over nuclear scans, CT, or MRI due to its availability, ability to detect the absence or presence of testicular blood flow, and lack of ionizing radiation. In a trained ultrasound operator, sensitivity and specificity approach 90% and 99%, respectively (8). The absence of blood flow to the affected testicle is noted in testicular torsion, whereas increased blood flow is noted in epididymitis and orchitis. Flow to the testicle will also be present in appendage torsion. Of course, these findings should be combined with the signs and symptoms, and not taken in isolation. Testicular anatomy is also easily visualized with ultrasound, helping to evaluate for testicular rupture, hematomas, and tumors. If the diagnosis is questionable, testicular ultrasound is the single most useful adjunct to the history and physical exam in the diagnosis of testicular torsion. It has been taught that a Doppler ultrasound should be performed on any and all testicular pain or swelling cases seeking emergency care. However, it is important to note that a high degree of clinical suspicion after history and physical exam is sufficient to warrant emergent surgical exploration of the scrotum, especially within the 6 hour window of symptom onset. Note that in the case above, the surgeon was called before the ultrasound was performed to give the surgeon more time to prepare for surgery since the clinical suspicion was high. Delaying surgery while waiting for an ultrasound examination can reduce the chances of testicular salvage.

Additional laboratory tests, including a CBC and urinalysis, can help to evaluate infectious etiologies of scrotal pain, but waiting for these results should not delay an ultrasound or surgery. A hernia, hydrocele, or varicocele can usually be distinguished on the physical exam, but if there remains any possibility of testicular torsion, an ultrasound should be obtained.

Acute testicular torsion requires emergent scrotal exploration and detorsion of the affected testicle. As viewed from below, the testes rotate inward or medially during torsion. Manual detorsion is achieved by rotating the testicle in the opposite direction (counterclockwise for a right torsion and clockwise for a left torsion). If testicular ischemia and necrosis persist after detorsion, the testicle is removed (orchiectomy). However, if blood flow and testicular viability are restored with detorsion, the testicle is then fixed to the scrotal wall (orchiopexy). In either case, the contralateral testicle should also be explored and fixed with a permanent suture. As noted above, the salvageability of a testicle within 6 hours of torsion is very good. Surgical exploration should still be performed even after 6 hours of symptom onset, since diminished fertility may result from leaving in an infarcted testicle. Fertility appears to be largely preserved in men with a history of testicular torsion that is promptly corrected with orchiopexy or unilateral orchiectomy (9).

Bacterial epididymitis and orchitis can be treated with empiric antibiotics based on the urinalysis or urine culture results. Sepsis, abscess formation, or Fournier gangrene may occasionally result from severe cases, requiring hospitalization with intravenous antibiotics. However, the majority of patients can be treated with outpatient antibiotics. Additional supportive care including analgesics, anti-inflammatory drugs, and scrotal elevation is recommended. Activity should be limited and any predisposing anatomic factors should be addressed (7). Viral orchitis is treated with similar supportive measures.

Acute testicular appendage torsion may be treated non-surgically with observation, and with analgesics and anti-inflammatory medications if the diagnosis is confirmed. The inflammatory reaction is self-limited and subsides in 3 to 10 days when the torsed appendage undergoes atrophy (5). Orchiopexy is not necessary since the appendix testis does not affect the attachment of the testicle to the scrotum. If the diagnosis is unclear, emergent scrotal exploration is indicated.

Trauma with rupture of the tunica albuginea of the testes requires exploration emergently, with debridement and repair. Penetrating injuries to the scrotum also merit surgical exploration since more than 50% of cases involve testicular injury (6). In blunt trauma, the incidence of testicular rupture varies widely. Ultrasonography is useful in these cases to determine the degree of testis injury and identify possible testicular rupture or hematoceles. Hematomas can be managed with observation, rest, cold packs, and analgesics. Henoch-Schonlein purpuric scrotal swelling may be managed medically. Neonatal torsion may require exploration if the diagnosis is made early enough, but unfortunately, the majority are diagnosed too late for testicle viability (4). Hernias and hydroceles should be repaired, emergently if incarcerated, electively if not.

In the acute scrotum presentation, a full range of scrotal pathology must be considered. Emergent scrotal exploration is indicated in cases with a high degree of suspicion for testicular torsion, as indicated by the history and physical exam, in testicular rupture, and in penetrating scrotal trauma. Ultrasound imaging is a very useful diagnostic tool in evaluating equivocal presentations of the acute scrotum.

1. What are the signs and symptoms that help to differentiate acute testicular torsion from epididymitis?
2. How is color Doppler ultrasound helpful in the differential diagnosis of acute scrotum?
3.What is the cremasteric Reflex? Prehn's sign? The blue dot sign? The bell-clapper deformity?
4. What is the time frame most advantageous to restoring the viability of a torsed testicle?
5. How is acute testicular torsion managed?
6. How is acute epididymitis managed?

1. Palmer LS, Palmer JS. Management of Abnormalities of the External Genitalia in Boys. In: Partin AW, Dmochowski RR, Kavoussi LR, Peters CA (eds). Campbell-Walsh-Wein Urology, 12th ed. 2021. Philadelphia, PA: Elsevier. pp:871-904.
2. MacDonald C, Kronfli R, Carachi R, O'Toole S. A systematic review and meta-analysis revealing realistic outcomes following paediatric torsion of testes. J Pediatr Urol. 2018;14(6):503-509. doi:10.1016/j.jpurol.2018.09.017
3. Fujita N, Tambo M, Okegawa T, Higashihara E, Nutahara K. Distinguishing testicular torsion from torsion of the appendix testis by clinical features and signs in patients with acute scrotum. Res Rep Urol. 2017;9:169-174. doi:10.2147/RRU.S140361
4. Kylat RI. Perinatal testicular torsion. Arch Pediatr. 2021;28(1):75-79. doi:10.1016/j.arcped.2020.10.006
5. Elder, JS. Disorders and Anomalies of the Scrotal Contents. In: Kliegman RM, St. Geme JW, Blum NJ, et al (eds). Nelson Textbook of Pediatrics, 21st edition. 2020, Elsevier, Philadelphia, PA. pp. 2827-2833.
6. Bourke MM, Silverberg JZ. Acute Scrotal Emergencies. Emerg Med Clin North Am. 2019;37(4):593-610. doi:10.1016/j.emc.2019.07.002
7. McConaghy JR, Panchal B. Epididymitis: An Overview. American Family Physician. Published November 1, 2016. Accessed April 3, 2022.
8. Bowlin PR, Gatti JM, Murphy JP. Pediatric Testicular Torsion. Surg Clin North Am. 2017;97(1):161-172. doi:10.1016/j.suc.2016.08.012
9. Gielchinsky I, Suraqui E, Hidas G, et al. Pregnancy Rates after Testicular Torsion. J Urol. 2016;196(3):852-855. doi:10.1016/j.juro.2016.04.066

Answers to questions
1. In testicular torsion, there is acute onset of pain. The cremasteric reflex is absent. Scrotal lie may be transverse and cephalad compared to normal. Testicular elevation does not reduce pain. Fever, pyuria, and dysuria are absent. However, clinical signs can be unreliable.
2. Blood flow to the testicles can be evaluated rapidly and the testicular anatomy can be assessed. Normal or increased blood flow is seen in epididymitis, while absent blood flow is indicative of torsion. Testicular rupture in trauma can also be identified as can testicular tumors.
3. Cremasteric reflex: Gently stroking the medial thigh elicits spermatic cord cremasteric muscle contraction and testicular movement. Prehn's sign: elevation of the affected testicle reduces the pain in epididymitis. Blue dot sign: a torsed ischemic testicular appendage may appear as a blue dot through the scrotal skin. Bell-clapper deformity: an incomplete attachment of the tunica vaginalis onto the testicle and epididymis, predisposing the testicle to torse more easily than if the normal posterior attachment of the tunica vaginalis to the testicle were present.
4. Detorsion within 6 hours of the onset of the torsion.
5. Emergent scrotal exploration and testicular detorsion with bilateral testicular fixation (if the testicle was salvageable) or orchiectomy and contralateral fixation (if the affected testicle was not salvageable).
6. Acute epididymitis is treated with antibiotics.

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