Approach to the Patient with Scrotal Swelling

Given the patient's age it is highly unlikely that he is suffering from a seminoma as this occurs around 40 years and would not present with acute pain. Hydrocele and epididymal cysts do present with testicular enlargement but the are usually painless. As the patient is apyrexic, he is unlikely to have a testicular infection

A positive Prehn's sign is when pain is relieved when the testicle is elevated. You would see this in epididimo-orchitis but not in testicular torsion and hence this is a useful sign to differentiate between the two.

During testicular torsion, anatomically the testicle rotates on its axis causing the spermatic cord twist like a ball on a string.

All the above anatomy is found in the spermatic cord. An easy way to remember this is the Rule of 3:

• 3 arteries: testicular, deferential, cremasteric
• 3 nerves: genital branch of the genitofemoral, cremasteric nerve*, sympathetic nerve fibres
• 3 fascias: external spermatic fascia, cremasteric fascia, internal spermatic fascia
• 3 other things: ductus deferens, pampiniform plexus, lymphatic vessels

During testicular torsion the veins are occluded first. This is because veins have a thinner wall and are easier to occlude versus the thicker, stronger and more elastic arteries. Subsequently this causes decreased venous return, pooling of blood, oedema and arterial compromise resulting in testicular ischemia and necrosis.

A doppler is important to assess blood in- and out- flow within the spermatic cord. However, testicular torsion is a surgical emergency. Time lost when ordering and undergoing investigations causes further testicular ischaemia and therefore a clinical diagnosis is sometimes enough to avoid delay to surgery. A differential for lower abdominal pain is UTIs. A positive urinalysis does not rule out testicular torsion, it does help with future management.

Typically the testicle turns medially. If the patient presents early and is waiting for a surgical review, attempts can be made to relieve the torsion. Manual detorsion involves externally rotating the testicle. This is done to relieve pain, but does not prevent torsion occurring again and therefore surgery is still needed.

To manage these patients the scrotum is opened and the testis is de-torted. A viable testicle will become a red colour indicating good blood flow and a orchidoplexy is performed (fixation of testicle to the tunica vaginalis).

If the testicle remains pale, dusky or black, although blood flow is restored, necrosis has occurred therefore the damage cannot be repaired and the testicle needs to be removed (orchidectomy)

Most commonly, testicular torsion is caused by the bell-clapper abnormality (intravaginal abnormality where there is a higher insertion point of the tunica vaginalis to the testis causing a lack of fixation of the posterolateral testicle to the scrotum). This is a bilateral abnormality and there is a high risk that the unaffected testicle may also become affected. Consequently, a bilateral orchidopexy is performed prophylactically.

David has presented with longer-standing pain as well as pathognomonic signs of infection. It is therefore more likely that he is suffering from acute epididymitis or epididymo-orchitis in contrast to testicular torsion.

Consequently it is important to assess risk factors for epididymo-orchitis within the history. Most commonly in this age group the most common cause are local infections from the lower urinary tract.

Positive Prehn's sign: pain is relieved upon testicular elevation counteracting gravity’s downward pull on the inflamed epididymis.

Cremaster reflex: As the spermatic cord is not affected, upon stroking the medial thigh the scrotum will elevate greater than 0.5cm proximally signifying this is not a testicular emergency.

When palpating the scrotum a lump may be felt however this will be an enlargement of the epididymis or testicle rather than presenting as a discrete lump.

Epididymitis in those aged between 14-35, it is most likely caused by a STI. Given David's age it is likely he is having sexual intercourse and susceptible to chlamydia or gonorrhoea infections. Currently, in the UK, chlamydia is much more common than gonorrhoea (although gonorrhoea is on the rise).

In those older than 35 years of age presenting with similar symptoms it is much more likely to be caused by enteric infections such as E. coli.

The British Association for Sexual Health and HIV recommends that chlamydia should be treated with doxycycline (100mg bd for 7 days) or azithromycin (1g orally as a single dose, followed by 500mg once daily for two days). Doxycycline may be slightly more effective. Patients should abstain from sexual activity until they have completed the course of doxycycline, or for seven days after completing treatment with azithromycin.

Ceftriaxone 500mg IM and Doxycycline 100mg PO O.D for 10-14 days (and no sexual activity for 14 days) is recommended when the causative organism is unknown.

Ceftriaxone is used to treat gonorrhoea.

David is 16 and therefore can consent to sexual activity so a referral to social services is not warranted. However a good sexual history should be taken. Due to the likelihood of unprotected sexual activity it would be beneficial to do a comprehensive STI check including HIV (especially if he has a male partner). It is also important to tell the patient to not have sex until the course of antibiotics have been taken so not to infect others. In addition he should be advised to tell his sexual partner/s so they too can get treatment and avoid getting himself re-infected.