Epididymoorchitis overview

# Overview
Epididymoorchitis refers to the inflammation of the epididymis and/or testes, with or without infection. It is a major cause of acute scrotum and must be differentiated from other common causes, such as testicular torsion and torsion of the testicular appendage. While the pathogenesis is not fully understood, infectious epididymoorchitis is thought to be due to retrograde reflux of infected urine into the epididymis, which then spreads to the testes. The causes of epididymoorchitis can be divided into idiopathic, infectious and non-infectious causes. Most common cases are due to infectious causes, which are mostly due to N. gonorrhea, C. trachomatis and E. Coli. Data on epidemiology of epididymoorchitis is scarce, however, epididymoorchitis is the 5th most common genitourinary diagnosis made and disease is more prevalent among U.S. military men. Peak incidence of the disease is in men between the ages of 20 to 29 years. The main symptoms of epididymoorchitis are scrotal pain and swelling. Other symptoms such as fever, nausea, vomiting and lower UTI symptoms may be present. The main focus of physical examination in patients with epididymoorchitis is scrotal and testicular examination. Signs that may be present include testicular swelling, tenderness on palpation, as well as erythema. Other signs include relief of pain upon elevation of the testis. Unlike patients with testicular torsion, patients with epididymoorchitis have an intact cremasteric reflex. A color Doppler ultrasound is mainly done to rule out testicular torsion and is the diagnostic imaging of choice in evaluating cases of acute scrotum. Epididymoorchitis might show a thickened epididymis with normal to increased Doppler wave pulsations, consistent with normal to increased blood flow. Management of epididymoorchitis consists mainly of conservative measures, including bed rest and limitation of physical activity, use of cold packs, analgesia and non-steroidal anti-inflammatory drugs (NSAIDs). In addition, appropriate antibiotic therapy should be initiated if the cause of epididymoorchitis is bacterial.

# Historical Perspective
Cases of epididymoorchitis were described in literature as early as 1841. It was believed that epididymitis was caused by chemical irritation caused by urine reflux. However, by 1979, a study showed that bacteria were responsible for more cases.

# Classification
Epididymoorchitis can be classified based on the extent of involvement into isolated cases of epididymitis, isolated cases of orchitis or cases of epididymoorchitis. Another means of classifying the disease is based on duration into acute or chronic epididymoorchitis. Finally, it can also be classified according to the causative agent into infectious, non-infectious and idiopathic causes.

# Pathophysiology
Epididymoorchitis refers to the inflammation of the epididymis and/or testes, with or without infection. While the pathogenesis is not fully understood, infectious epididymoorchitis is thought to be due to retrograde reflux of infected urine into the epididymis, which then spreads to the testes.

# Causes
The causes of epididymoorchitis can be divided into idiopathic, infectious and non-infectious causes.

# Differentiating Epididymoorchitis from other Diseases
Epididymoorchitis is a major cause of acute scrotum. Other causes of acute scrotum which must be differentiated from epididymoorchitis include testicular torsion and torsion of the testicular appendage.

# Epidemiology and Demographics
Data on epidemiology of epididymoorchitis is scarce, however, epididymoorchitis is the 5th most common genitourinary diagnosis made and disease is more prevalent among U.S. military men. Peak incidence of the disease is in men between the ages of 20 to 29 years.

# Risk Factors
Risk factors for epididymoorchitis include sexual activity and sexually transmitted diseases, surgery or instrumentation of the bladder, as well as anatomic abnormalities of the urinary tract and obstruction to the normal flow of urine.

# Screening
There are no screening recommendations for epididymoorchitis.

# Natural History, Complications and Prognosis
The prognosis of epididymoorchitis is usually excellent, with the majority of cases resolving within 30 days of initiation of medical therapy. However, some cases can progress to chronic epididymoorchitis. Other complications of epididymoorchitis include abscess formation, testicular infarction, sepsis and infertility.

# History and Symptoms
The main symptoms of epididymoorchitis are scrotal pain and swelling. Other symptoms such as fever, nausea, vomiting and lower UTI symptoms may be present.

# Physical Examination
The main focus of physical examination in patients with epididymoorchitis is scrotal and testicular examination. Signs that may be present include testicular swelling, tenderness on palpation, as well as erythema. Other signs include relief of pain upon elevation of the testis. Unlike patients with testicular torsion, patients with epididymoorchitis have an intact cremasteric reflex.

# Laboratory Findings
In patients with epididymoorchitis, laboratory investigations include a urinalysis, urine culture, as well as urethral Gram stain and PCR testing for N. gonorrhea and C. trachomatis.

# X Ray
There are no x-ray findings associated with epididymoorchitis.

# CT
Imaging studies, such as CT scan, are usually not done in the case of epididymoorchitis. The diagnostic modality of choice is a scrotal ultrasound.

# MRI
Imaging studies, such as MRI, are usually not done in the case of epididymoorchitis. The diagnostic modality of choice is a scrotal ultrasound.

# Ultrasound
A color Doppler ultrasound is mainly done to rule out testicular torsion and is the diagnostic imaging of choice in evaluating cases of acute scrotum. Epididymoorchitis might show a thickened epididymis with normal to increased Doppler wave pulsations, consistent with a normal to increased blood flow.

# Other Imaging Findings
A scrotal radionuclide scintigraphy has a high specificity and sensitivity in distinguishing between testicular torsion and epididymoorchitis. In testicular torsion, there is decreased or absent uptake of radionuclide, while uptake is increased in cases of epididymoorchitis.

# Other Diagnostic Studies
There are no other diagnostic studies for epididymoorchitis.

# Medical Therapy
Management of epididymoorchitis consists mainly of conservative measures, including bed rest and limitation of physical activity, use of cold packs, analgesia and non-steroidal anti-inflammatory drugs (NSAIDs). In addition, appropriate antibiotic therapy should be initiated if the cause of epididymoorchitis is bacterial.

# Surgery
There is no role for surgery in treating uncomplicated cases of epididymoorchitis.

# Primary Prevention
In men aged 14 to 35 years, cases of epididymoorchitis are mainly due to sexually transmitted infections. Hence, the importance of condom use to prevent the disease should be emphasized.

# Secondary Prevention
Secondary prevention of epididymoorchitis mainly consists on emphasizing on the importance of completion of the antibiotic course if prescribed, screening and treating comorbid sexually transmitted infections in both the patient and his partners.