Orchitis

Etiology

Various bacteria and viruses cause orchitis.

• Orchitis in young patients is usually viral, with mumps and rubella being the most common causes. Reports exist of cases of orchitis after the measles, mumps, and rubella (MMR) vaccine.[3]
• Other viruses include coxsackievirus, varicella, echovirus, and cytomegalovirus.
• Bacterial infections of the prostate and urinary tract infection can cause orchitis. Common causes of bacterial orchitis include Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus and Streptococcus species.
• Bacteria that can cause sexually transmitted infections can also cause orchitis in sexually active males. Common organisms are Neisseria gonorrhoeae, Chlamydia trachomatis, and Treponema pallidum
• Mycobacterium avium complex, Cryptococcus neoformans, Toxoplasma gondii, Haemophilus parainfluenzae, and Candida albicans have been reported to cause orchitis in immunocompromised patients.

There are also reports of orchitis caused by autoimmunity, which can classify as primary and secondary.[4]

Epidemiology

Orchitis alone is very uncommon and is usually accompanied by epididymitis, hence the true incidence is unclear. Current literature also does not suggest any predilection for any race or religion.

Orchitis develops in 14% to 35% of postpubertal patients with mumps. Symptoms develop 4 to 8 days after parotitis but can also occur in the absence of parotitis. Mumps virus is responsible for most of the cases of isolated orchitis.

Pathophysiology

Orchitis is the inflammation of the testis, and isolated acute orchitis is a very rare phenomenon.[5] Orchitis is usually unilateral, and symptoms can vary from mild to severe. Most cases resolve by the end of two weeks. There are two significant differences between orchitis and infections of other male accessory sex organs:

• The primary route of the spread of infection to the testis is blood-borne dissemination.[2]
• Viruses are implicated as significant pathogens.

Common risk factors include a preexisting history of epididymitis, unprotected sexual contact, multiple sexual partners, long-term use of foley catheter, bladder outlet obstruction, structural abnormality, and lack of immunization with MMR vaccination (vaccination reduces the risk of developing orchitis after mumps).[6]

History and Physical

The patient usually presents with acute onset of testicular pain, which may initially involve one testis, and then may spread to include the whole scrotum. The patient may also complain of fever accompanied by malaise, fatigue, and chills.

Examination findings may include testicular enlargement, tenderness, and induration. Scrotal edema and erythema may also be present. The epididymis may also be enlarged if orchitis is accompanied by epididymitis. The cremasteric reflex is normal in affected individuals. Mumps orchitis may present with bilateral parotid enlargement and usually present 4 to 8 days after onset of parotitis.

When evaluating such patients, the clinician should also note various risk factors so that they can receive appropriate management.

Evaluation

Orchitis diagnosis is usually from history and physical findings. Laboratory tests are generally not helpful, but urethral swabs and urine samples may be obtained for routine examination and cultures to rule out urinary tract infection and diagnose sexually transmitted infections as the source.

When assessing patients with acute testicular or scrotal pain, it is imperative to rule out testicular torsion. For such patients, color Doppler ultrasonography of the scrotum is the first choice of investigation.

Ultrasonography findings in patients with mumps orchitis usually subside by the seventh day.[7] Although not typically done, serum immunofluorescence antibody testing is useful to confirm the diagnosis of mumps orchitis.

Treatment / Management

In an emergency, clinicians must distinguish between torsion and inflammation of the testis. Antibiotics are not necessary for viral causes of the disease. Supportive therapies such as bed rest, antipyretics, analgesics, scrotal support, and hot or cold packs for analgesia are advisable.

Antibiotics should start empirically based on the likely pathogens according to age and sexual history.

• If there is suspicion of an enteric bacteria is suspected, then fluoroquinolones (ciprofloxacin, ofloxacin, levofloxacin) for 10 to 14 days are the preferred drugs. Trimethoprim-sulfamethoxazole is also an option for these pathogens.
• If there is suspicion of a sexually transmitted pathogen, then treatment should consist of ceftriaxone 250 mg single shot intramuscularly and doxycycline 100 mg twice daily for 10 to 14 days. Azithromycin is also an option in place of doxycycline.

Sexual partners of the patient with sexually transmitted pathogens should receive treatment.[8] The inability to take oral antibiotics, signs of sepsis, and failure of previous outpatient therapy should warrant inpatient therapy.

Differential Diagnosis

Careful evaluation for probable reasons for acute scrotal pain and swelling is essential for the efficient management of the patients. Testicular torsion is the most significant differential as urgent exploration is required.[9] Other differentials include:

• Abscess formation
• Hydrocoele
• Epididymitis (often coexist)

Prognosis

Overall, the majority of viral cases and antibiotic-treated cases will resolve without any complications. Most of the patients are treated as outpatients. The swelling and tenderness may persist even after antibiotic therapy but should be significantly improved. In case of persistence, compliance should be checked, and receive further evaluation if required. The decrease in body temperature in the first three days of antibacterial treatment is considered a good prognostic marker.[10] Most cases of mumps orchitis also resolve within ten days.

Complications

Complications are preventable with accurate diagnosis and efficient management of patients.[11] Most patients recover without sequelae; however, there are reports of the following complications:

• Testicular atrophy (up to 60% of cases demonstrate some degree of atrophy)
• Impaired fertility
• Sterility (rare)
• Epididymitis
• Reactive hydrocele

Rarely in cases of pyogenic orchitis and testicular infarction, an abscess can be formed which requires surgical consultation for management.