Acute scrotum: testicular torsion and its mimics
How to assess a child with sudden testicular pain correctly, avoid missing torsion, and refer to a pediatric urologist without losing time on ultrasound.
Step 1 of 13
Objectives
After this course you will be able to
- List the main causes of acute scrotum and know their likelihood by age.
- Distinguish testicular torsion from torsion of the appendix testis and from epididymitis by clinical signs.
- Calculate the TWIST score and know its limitations.
- Explain the role of Doppler ultrasound and why normal blood flow does not rule out torsion.
- Know when and how to refer the child urgently.
Key message: sudden-onset testicular pain is a surgical emergency until torsion has been ruled out. Time determines the fate of the testis; there must be no waiting for ultrasound or observation.
Basics
Testicular torsion in numbers
- 90–100%salvage within the first 6 hours
- ~50%after 12 hours
- <10%after 24 hours
- 12–18 yearsthe most common age
Torsion has two peaks: the neonatal period and adolescence. In adolescents, torsion often starts during sleep, after sports or after minor trauma.
A substantial share of cases that end in loss of the testis are related to late presentation or late referral: the pain is assessed as "abdominal pain", the child is given an analgesic and sent home, or ultrasound is awaited.
Basics
Causes of acute scrotum
| Cause | Typical age | Key feature |
|---|---|---|
| Testicular torsion | Newborn, 12–18 years | Sudden, severe pain, nausea, vomiting |
| Torsion of the appendix testis | 7–12 years | Gradually increasing pain, point tenderness at the upper pole, "blue dot" |
| Epididymitis, orchitis | Any age, more common in adolescents | Gradual-onset pain, posterior tenderness, sometimes dysuria |
| Incarcerated inguinal hernia | Infants | Firm swelling extending from the groin into the scrotum, vomiting |
| Idiopathic scrotal edema | 4–7 years | Bilateral redness and edema, little pain, testis not tender |
| Henoch-Schönlein purpura | Childhood | Purpura on the legs, together with joint and abdominal pain |
| Trauma, tumor, hydrocele | Any age | Distinguished by history and examination |
The most common cause of acute scrotum is torsion of the appendix testis, and the most dangerous is testicular torsion. The decision is driven by danger, not by likelihood.
Basics
Anatomy of torsion
Intravaginal torsion (adolescents): the tunica vaginalis surrounds the testis high up along the spermatic cord, and the testis hangs freely like the clapper of a bell (bell clapper deformity). This anatomic predisposition is often bilateral.
Extravaginal torsion (newborns): because the tunica vaginalis is not yet fixed to the scrotum, the testis twists together with its coverings. It often occurs in utero.
Intermittent torsion: short episodes of severe pain that resolve on their own. Each episode is a warning of a subsequent complete torsion and an indication for elective orchiopexy.
Diagnosis
History and examination
- Record the exact time the pain started, to the hour. This is the key parameter for subsequent decisions.
- Did the pain start suddenly or build up gradually? Nausea and vomiting strongly suggest torsion.
- Have there been similar episodes before that resolved on their own (intermittent torsion)?
- Dysuria, fever, urinary tract anomaly, recent viral infection, trauma.
Examination: first inspect with the child standing and lying down, then palpate, starting on the unaffected side.
| Sign | Torsion | Appendix torsion | Epididymitis |
|---|---|---|---|
| Onset | Sudden | Gradual | Gradual |
| Position of the testis | High-riding, horizontal lie | Normal | Normal |
| Tenderness | Entire testis | Point tenderness at the upper pole | Posterior, over the epididymis |
| Cremasteric reflex | Usually absent | Present | Present |
| Vomiting | Common | Rare | Rare |
If an adolescent boy presents with abdominal pain, the scrotum must be examined. Out of embarrassment, adolescents often complain of abdominal pain rather than testicular pain.
Diagnosis
TWIST score
TWIST (Testicular Workup for Ischemia and Suspected Torsion) is a simple clinical score for assessing the likelihood of torsion.
| Sign | Points |
|---|---|
| Testicular swelling | 2 |
| Hard testis | 2 |
| Absent cremasteric reflex | 1 |
| Nausea or vomiting | 1 |
| High-riding testis | 1 |
| Total score | Risk | Approach |
|---|---|---|
| 0–2 | Low | Torsion is unlikely, but the child should be assessed by a pediatric urologist or surgeon |
| 3–4 | Intermediate | Urgent Doppler ultrasound and surgical consultation |
| 5–7 | High | Urgent surgical exploration without waiting for ultrasound |
TWIST helps with decision-making, but a low score does not completely rule out torsion. For the pediatrician the conclusion is the same: a child with sudden testicular pain is referred for surgical assessment the same day.
Diagnosis
Doppler ultrasound: when and how?
- Doppler ultrasound can show blood flow in the testis, twisting of the spermatic cord (the "whirlpool" sign) and other causes.
- Normal or reduced blood flow does not rule out torsion: flow may be preserved in partial or intermittent torsion.
- The result depends heavily on the experience of the person performing the study.
- If clinical suspicion is high, ultrasound must not delay surgery.
The most common error: sending the child home because "there is flow on ultrasound". If the clinical picture is consistent with torsion, surgical exploration is needed.
Diagnosis
Torsion in the newborn
In torsion that occurs before birth, the scrotum is hard, bluish and painless at birth; salvaging the testis is often not possible. In torsion that develops after birth, a previously normal scrotum suddenly swells and changes color.
- Torsion that develops after birth is an emergency.
- In torsion that occurred before birth, the child is also referred to a pediatric urologist the same day: fixation of the contralateral testis is discussed, because bilateral torsion is rare but catastrophic.
Treatment
Referral: what should the pediatrician do?
- Sudden testicular pain
- Record the time the pain started
- Nothing by mouth
- Refer immediately to a center with surgical services and call ahead
- Do not give the child an analgesic and send him home, and do not wait until morning.
- Do not delay referral for an ultrasound result.
- Even if the pain has resolved, the child should be examined the same day: the torsion may have untwisted on its own.
Treatment
Surgical treatment
Scrotal exploration: the scrotum is opened, the twisted spermatic cord is untwisted and the viability of the testis is assessed.
- If the testis is viable: orchiopexy (the testis is sutured to the scrotum).
- If the testis is necrotic: orchiectomy.
- In both cases the contralateral testis is also fixed, because the anatomic predisposition is often bilateral.
Manual detorsion: if surgical care is delayed, an experienced physician may rotate the testis from medial to lateral (the "opening a book" direction). Sudden relief of pain indicates success. This is only a temporary measure and does not replace surgery.
Treatment
Treatment of appendix torsion and epididymitis
Torsion of the appendix testis: once testicular torsion has been reliably ruled out, conservative treatment: rest, anti-inflammatory analgesic. The pain usually resolves within 3–10 days. If the pain persists or the diagnosis is uncertain, exploration is performed.
Epididymitis: in prepubertal children it is often sterile, postviral or reactive. If urinalysis is normal, antibiotics are not needed: rest, analgesic. With pyuria or a positive culture, antibiotics are prescribed and the urinary tract is assessed with ultrasound. In a sexually active adolescent, sexually transmitted infections are considered.
Recurrent epididymitis may point to a urinary tract anomaly (ectopic ureter, urethral problems, voiding dysfunction) and should be investigated by a pediatric urologist.
Treatment
Follow-up
- After torsion, the testis is checked for size and consistency over 6–12 months: atrophy is possible.
- The adolescent is taught testicular self-examination.
- A child with intermittent pain episodes is referred for elective orchiopexy.
- The family is told that sudden testicular pain requires immediate medical attention.
The pediatrician's role: treat sudden testicular pain as an emergency, examine the scrotum in an adolescent with abdominal pain, and refer the child without losing time on ultrasound and observation.
Quiz
Quiz: Acute scrotum
Test yourself: choose one answer.
-
A 14-year-old boy woke up at night with severe pain in the left testis and has vomited twice. The testis is high-riding and the cremasteric reflex is absent. What is the most appropriate step?
Sudden pain, vomiting, a high-riding testis and an absent cremasteric reflex are typical of torsion (high TWIST). The child is referred for urgent surgical exploration without waiting for ultrasound.
-
Doppler ultrasound shows blood flow in the testis, but the clinical picture is consistent with torsion. What should be done?
Blood flow may be preserved in partial or intermittent torsion. A normal Doppler does not rule out torsion; if clinical suspicion is high, surgery is not delayed.
-
A 9-year-old child has had gradually increasing pain for 2 days, with point tenderness at the upper pole of the testis and a blue dot visible through the skin. What is the most likely diagnosis?
Point tenderness at the upper pole and a "blue dot" are typical of torsion of the appendix testis. Conservative treatment is given once testicular torsion has been reliably ruled out.
-
Which signs score 2 points in the TWIST score?
Testicular swelling and a hard testis score 2 points each; absent cremasteric reflex, nausea or vomiting, and a high-riding testis score 1 point each.
-
At surgery for torsion, the testis is viable. What is done with the contralateral testis?
The anatomic predisposition to torsion is often bilateral, so the contralateral testis is also fixed during the same operation.
Course completed
Related articles for parents
Sources
- EAU Guidelines on Paediatric Urology, 2025: Acute scrotum in children.
- Barbosa JA, Tiseo BC, Barayan GA, et al. Development and initial validation of a scoring system to diagnose testicular torsion in children. J Urol. 2013;189(5):1859–1864.
- Mellick LB, Sinex JE, Gibson RW, Mears K. A systematic review of testicle survival time after a torsion event. Pediatr Emerg Care. 2019;35(12):821–825.
This material is intended for medical professionals and is based on current clinical guidelines. Decisions about an individual patient are made by the treating doctor.