Diagnostic Challenges in Atypical Mpox Presentations
The recent global outbreak of the Mpox virus—a zoonotic infection from the Orthopoxvirus family—has shifted from its traditional presentation. While classic cases often involved synchronous skin lesions, the 2022 outbreak and subsequent surges have shown a higher prevalence of gastrointestinal involvement.
A recent case involving a 51-year-old male highlights the diagnostic complexity. The patient presented with severe anorectal pain, diarrhea, and tenesmus without initial skin rashes. Imaging via CT scan revealed diffuse rectal wall thickening and mesorectal lymphadenopathy. It was not until the fifth day of hospitalization—when pustular lesions emerged on the face, palms, and perianal region—that Mpox was suspected and later confirmed via PCR testing.
Pro Tip: In patients presenting with acute proctitis, clinicians should perform a thorough dermatological exam and consider swabbing mucosal lesions for Mpox PCR even if no systemic rash is present.
The Role of Comorbidities in Disease Severity
Medical literature suggests that the severity of Mpox may be exacerbated by underlying health conditions. In the documented case, the patient suffered from poorly controlled diabetes mellitus, with a glycosylated hemoglobin level of 13.9%. While the direct link between metabolic dysfunction and Mpox progression requires further study, clinicians note that immunocompromised patients—including those with HIV or solid organ transplants—are at a significantly higher risk for severe complications such as necrotizing skin lesions, encephalitis, and myocarditis.
The World Health Organization (WHO) has highlighted that high viral loads of the Mpox virus are detectable in semen, saliva, and feces. Because of this, the virus is primarily transmitted through close human-to-human contact, including sexual activity. This makes the distinction between Mpox-related proctitis and other sexually transmitted infections (STIs) like syphilis or gonorrhea critical, as coinfection rates are estimated at 15–30% in some populations.
Future Trends: Point-of-Care Testing and Surveillance
These tools allow for bedside diagnosis, which is vital for patients with atypical, GI-dominant presentations.
Global health authorities, including the WHO, declared a Public Health Emergency of International Concern in August 2024 following a surge in Clade I cases in the Democratic Republic of the Congo. This underscores the need for ongoing vigilance. Future surveillance efforts will likely focus on:
- Histopathological Awareness: Recognizing that rectal biopsies may show non-specific acute colitis, necessitating molecular testing to confirm the diagnosis.
- Regional Monitoring: Maintaining high index of suspicion in regions where the disease was previously considered rare, such as the Middle East.
Did you know? The WHO officially renamed “monkeypox” to “Mpox” in November 2022 to avoid the stigmatization associated with the original name.
Frequently Asked Questions (FAQ)
Can Mpox cause rectal symptoms without a skin rash?
Yes. Mpox can manifest as severe proctitis, causing rectal pain, tenesmus, and mucosal ulceration before any visible skin lesions appear on the body.
How is Mpox proctitis diagnosed?
The gold standard for diagnosis is real-time PCR testing. Swabs should be taken directly from skin lesions or, in their absence, from mucosal specimens in the anorectum.
Why is Mpox considered a diagnostic challenge for gastroenterologists?
Because the initial symptoms often mimic common inflammatory bowel conditions or other STIs, the diagnosis is frequently delayed, especially in regions where the virus is not endemic.
Have you encountered or treated cases of atypical viral proctitis? Share your experiences in the comments below or subscribe to our clinical newsletter for the latest updates on emerging infectious diseases.
