What are the differential diagnoses for mumps in a male patient?

Differential Diagnoses for Mumps in Male Patients

When evaluating a male patient with suspected mumps, you must consider that parotitis has multiple infectious and noninfectious causes, and laboratory confirmation is essential since one-third of clinically diagnosed mumps cases lack serologic evidence of actual mumps infection. 1

Key Clinical Context

The ACIP guidelines explicitly state that "parotitis may have other infectious and noninfectious causes" and emphasize that clinical diagnosis alone is unreliable. 1 Additionally, mumps can present without parotid involvement—parotitis is absent in 10-30% of symptomatic mumps cases, making the differential diagnosis even more critical. 2

Infectious Differentials

Viral Causes

• Other viral parotitis: Epstein-Barr virus (EBV), cytomegalovirus (CMV), HIV, influenza A, parainfluenza viruses, adenovirus, and enteroviruses can all cause parotid swelling mimicking mumps 1, 3
• HIV infection: Should be tested in all patients with suspected mumps or parotitis, as HIV can present with parotid swelling during acute seroconversion or as chronic parotitis in advanced disease 1
• Enterovirus infections: Can cause parotitis and may be isolated from throat/rectal swabs or vesicles if present 1

Bacterial Causes

• Bacterial parotitis (typically Staphylococcus aureus or Streptococcus species): Usually presents with more acute onset, purulent discharge from Stensen's duct, and systemic toxicity 3
• Mycobacterial infections: Can cause chronic parotid swelling 3

Noninfectious Differentials

Salivary Gland Disorders

• Salivary duct obstruction/sialolithiasis: Presents with intermittent swelling, especially with meals 3
• Chronic sialadenitis: Recurrent or persistent gland swelling 3
• Sjögren's syndrome: Bilateral parotid enlargement with sicca symptoms 3

Neoplastic Causes

• Salivary gland tumors: Both benign (pleomorphic adenoma) and malignant tumors can present as parotid masses 3
• Lymphoma: Can involve parotid glands 3

Other Causes

• Drug-induced parotitis: Certain medications can cause parotid swelling 3
• Metabolic conditions: Diabetes, cirrhosis, malnutrition can cause parotid enlargement 3

Male-Specific Considerations

In male patients specifically, if orchitis is present without clear parotitis, the differential expands significantly:

• Bacterial epididymo-orchitis: Most commonly from E. coli, Chlamydia trachomatis, or Neisseria gonorrhoeae in sexually active men 4
• Testicular torsion: Surgical emergency requiring immediate differentiation 4
• Testicular tumor: Can present with painless or painful testicular swelling 4
• Isolated mumps orchitis: Can occur without parotid involvement, as documented in cases of submandibular-only mumps infection 4

Critical Diagnostic Approach

The guidelines mandate laboratory confirmation for all suspected mumps cases through: 1

• Mumps IgM antibody testing
• Viral isolation from parotid duct swabs (after massaging gland for 30 seconds) or buccal swabs
• PCR from appropriate specimens
• Acute and convalescent IgG titers showing significant rise

A common pitfall: Relying solely on clinical diagnosis leads to misdiagnosis in approximately one-third of cases, as demonstrated in prospective Canadian studies. 1 Always obtain serologic or virologic confirmation, especially since mumps can present atypically (without parotitis in 10-30% of cases or affecting only submandibular glands). 4, 2