From the Guidelines
For a male patient presenting with a penile lesion, I recommend ordering a combination of laboratory tests to screen for sexually transmitted infections, including PCR tests for herpes simplex virus, chlamydia, and gonorrhea, as well as serological tests for syphilis and HIV. These tests are crucial for identifying the underlying cause of the lesion, as various STIs can present with similar symptoms but require different treatments. According to the 2018 update by the Infectious Diseases Society of America and the American Society for Microbiology 1, high-risk individuals, such as men who have sex with men (MSM), should have extragenital sites evaluated for GC and CT, but this may not be directly applicable to all male patients presenting with a penile lesion. Key laboratory tests to consider include:
- PCR test for herpes simplex virus (HSV-1 and HSV-2)
- Dark-field microscopy or PCR for Treponema pallidum (syphilis)
- Serum RPR or VDRL with confirmatory treponemal testing for syphilis
- HIV testing
- PCR testing for chlamydia and gonorrhea from a urethral swab It is essential to note that some infections, like syphilis, can have systemic consequences if left untreated, while others, like herpes, require specific antiviral therapy 1. The patient should abstain from sexual activity until results are available and treatment is completed if an infection is identified. Additionally, consideration should be given to testing for other STIs, such as Mycoplasma genitalium, which is recognized as a cause of nongonococcal urethritis in males 1.
From the Research
Laboratory Tests for STI Screening in Males
To screen for sexually transmitted infections (STIs) in a male patient presenting with a lesion on the penis, the following laboratory tests can be ordered:
- Nucleic acid amplification tests (NAATs) for chlamydia and gonorrhea, as these infections are common and can cause lesions on the penis 2
- Herpes simplex virus (HSV) testing, including type-specific identification, using a commercially available nucleic acid amplification test 3
- Syphilis testing, as it is a bacterial STI that can cause lesions on the penis 4
- Human immunodeficiency virus (HIV) testing, as it is a viral STI that can increase the risk of other STIs 5
- Human papillomavirus (HPV) testing, as it is a viral STI that can cause lesions on the penis 5
Considerations for STI Screening
When screening for STIs, it is essential to consider the following:
- The use of symptomology alone is not an effective way to diagnose STIs, as many infections can be asymptomatic 2
- Molecular methods, such as NAATs, have facilitated personalized therapy and follow-up regimens targeted for individual types or strains of some STIs 5
- Quality-assured diagnostic tests for STIs are necessary to ensure accurate diagnosis and treatment 4
- Self-sampling for rectal STI is a feasible and acceptable option for men who have sex with men (MSM) 6