Dark field examination, any source (eg, penile, vaginal, oral, skin); includes specimen collection
CPT4 code
Name of the Procedure:
Dark Field Examination (Dark Field Microscopy)
Summary
A dark field examination is a diagnostic test that involves using a specialized microscope to observe unstained specimens from various sources, such as penile, vaginal, oral, or skin, to detect the presence of bacteria or other pathogens that may not be visible using standard light microscopy.
Purpose
The primary purpose of a dark field examination is to diagnose infections like syphilis by identifying the causative bacteria, Treponema pallidum. The test helps in accurately detecting pathogens to expedite effective treatment.
Indications
- Unexplained lesions or ulcers on the genitals, skin, or mucous membranes.
- Symptoms of sexually transmitted infections (STIs), such as unusual discharge, sores, or rashes.
- Suspected cases of syphilis and other spirochetal infections.
- Follow-up examination post-treatment for STIs to ensure eradication.
Preparation
- Patients may need to avoid applying ointments, creams, or other topical agents to the area of concern prior to specimen collection.
- No special fasting or medication adjustments are usually required.
- Inform the healthcare provider about any medications or existing medical conditions.
Procedure Description
Specimen Collection:
- For genital, oral, or skin lesions, the healthcare provider will gently swab the area to collect a fluid sample or scrape the lesion to obtain cells.
- The sample is placed on a glass slide.
Microscopy:
- The slide is immediately examined using a dark field microscope in a dimly lit room. This technology enhances the contrast in unstained samples, making live bacteria appear bright against a dark background.
Duration
- The procedure itself usually takes about 10 to 20 minutes, including specimen collection and microscopy.
Setting
- The test is typically performed in a hospital, outpatient clinic, or specialized diagnostic lab with appropriate microscopy equipment.
Personnel
- A healthcare provider, such as a nurse, physician, or trained laboratory technician performs the specimen collection.
- A laboratory technician or pathologist performs the microscopy.
Risks and Complications
- Minor discomfort during specimen collection.
- Rare instances of minor bleeding or irritation from sample collection.
- Low risk of infection at the collection site.
Benefits
- Early diagnosis of infections, facilitating prompt treatment.
- Accurate detection of pathogens not easily visible with standard microscopy, improving diagnostic accuracy.
Recovery
- No significant recovery time is needed.
- Patients may resume normal activities immediately after the procedure.
- Follow-up appointments may be advised for discussing results and further treatment if necessary.
Alternatives
- Serological tests for syphilis and other STIs.
- Polymerase Chain Reaction (PCR) testing for pathogen DNA.
- Pros: Dark field examination provides immediate results; PCR is more specific but takes longer.
- Cons: Serological tests may take time to reflect acute infections and miss early-stage infections.
Patient Experience
- The patient may feel mild discomfort during specimen collection, but the procedure is usually well-tolerated.
- Pain management is typically not necessary due to the minimally invasive nature of the test.
- Patients can expect clear communication from healthcare providers regarding results and next steps in management.