CPT® Code 95052

1. Indications

Photo patch tests are indicated for the evaluation of patients suspected of having photoallergic contact dermatitis. This condition may arise from exposure to specific allergens that provoke a skin reaction when combined with sunlight. The following are common indications for performing photo patch tests:

• Suspected Photoallergic Contact Dermatitis Patients presenting with symptoms consistent with photoallergic contact dermatitis, such as localized skin reactions that occur upon sun exposure, may require this testing to identify the responsible allergens.
• History of Allergic Reactions Individuals with a documented history of allergic reactions to certain substances, particularly those that may be activated by UV light, are candidates for photo patch testing to determine specific sensitivities.
• Unexplained Dermatitis Patients experiencing dermatitis that does not respond to standard treatments or whose symptoms are exacerbated by sun exposure may benefit from this diagnostic approach to uncover underlying allergic triggers.

2. Procedure

The photo patch testing procedure involves several detailed steps to ensure accurate diagnosis and evaluation of allergic reactions. The following outlines the procedural steps:

• Preparation of Allergens Two patches are prepared for each allergen being tested. These patches are designed to deliver the allergens directly to the skin for assessment of allergic reactions.
• Application of Patches The prepared patches are symmetrically applied to each side of the patient's back. This symmetrical placement is crucial for comparative analysis of reactions on both sides.
• Initial Observation Period The patches remain in place for a total of 48 hours. During this time, the patient is instructed to refrain from bathing and to avoid activities that may cause heavy perspiration, as these factors could interfere with the test results.
• Patch Removal and Initial Evaluation After 48 hours, the patches are carefully removed by the healthcare professional. The skin is then examined for any signs of allergic reactions, such as redness or inflammation, and the initial results are documented in a written report.
• UV Exposure Following the initial evaluation, one side of the back is shielded from UV light while the other side is exposed to a UV light source. This step is essential for assessing potential photoallergic reactions.
• Initial UV Evaluation Approximately 30 minutes after UV exposure, an initial evaluation of the exposed side is conducted. The results of this evaluation are recorded for further analysis.
• Final Evaluation The patient returns for a final evaluation between 48 to 76 hours after the UV exposure. During this visit, the physician assesses the skin again to determine the absence, presence, or degree of any photoallergic reactions to the allergens tested.

3. Post-Procedure

After the completion of the photo patch test, patients may be advised on specific post-procedure care to ensure optimal healing and accurate interpretation of results. It is important for patients to follow any instructions provided by their healthcare professional regarding skin care and activities following the test. The physician will provide a comprehensive report detailing the findings, including the presence or absence of allergic reactions to each tested allergen. Patients may also receive guidance on avoiding identified allergens and managing any reactions that may occur as a result of the testing process.