95024

Intracutaneous (intradermal) tests with allergenic extracts, immediate type reaction, including test interpretation and report, specify number of tests

Current Procedural Terminology (CPT) code 95024 represents intracutaneous, or intradermal, allergy testing utilizing allergenic extracts to identify immediate type (IgE-mediated) hypersensitivity reactions. This highly specific diagnostic procedure is typically indicated when a patient presents with a strong clinical history suggestive of an allergic etiology—such as allergic rhinitis, allergic asthma, venom hypersensitivity, or specific drug allergies like penicillin—but has yielded negative or equivocal results on initial percutaneous (scratch or prick) testing. Because intradermal testing is far more sensitive than prick testing, it serves as an essential secondary step in a comprehensive allergy evaluation. During the procedure, the clinician or trained clinical staff injects a minuscule volume, usually between 0.02 mL and 0.05 mL, of a precisely diluted aqueous allergenic extract directly into the dermal layer of the patient's skin, typically on the volar aspect of the forearm or the outer aspect of the upper arm. The injection is performed using a fine-gauge needle, often 26 or 27 gauge, attached to a tuberculin syringe, creating a small, superficial bleb measuring approximately 2 to 3 millimeters in diameter. A positive (histamine) and a negative (saline) control are also administered concurrently to establish a baseline for reactivity and ensure the test's validity. The patient is closely monitored for 15 to 20 minutes, after which the clinician meticulously measures the resultant wheal (the raised, edematous center) and flare (the surrounding erythema) responses in millimeters. The interpretation of these local skin reactions is compared against the controls to definitively identify the offending allergens. Due to the systemic absorption potential and the heightened sensitivity of this testing modality, there is an inherent risk of inducing a severe systemic allergic reaction, including anaphylaxis. Consequently, the procedure mandates direct physician supervision, ensuring that emergency resuscitation equipment, epinephrine, and trained personnel are immediately available to manage any adverse events. The code inherently includes both the execution of the test itself and the professional interpretation and formalized reporting of the results. It is quantified and billed based on the precise number of individual allergenic tests administered.

Clinical Indications

  • Evaluation of patients with clinical symptoms of IgE-mediated allergic diseases (e.g., allergic rhinitis, allergic asthma) who have negative or equivocal percutaneous (prick/scratch) test results.
  • Assessment of suspected venom hypersensitivity, such as severe allergic reactions following Hymenoptera stings (bees, wasps, hornets, yellow jackets).
  • Diagnostic workup for suspected beta-lactam or penicillin drug allergies to determine current sensitization status and guide antibiotic therapy.
  • Investigation of specific environmental allergen sensitivities where high clinical suspicion remains despite negative preliminary prick testing.
  • Evaluation of potential vaccine allergies or specific biologic agents before initiating or continuing necessary treatments.

Procedure Steps

  1. Review the patient's complete medical history, previous percutaneous allergy test results, and ensure potentially interfering medications (such as antihistamines) have been appropriately withheld.
  2. Select the specific allergenic extracts to be tested based on the patient's clinical history and prepare precise dilutions, typically ranging from 1:1000 to 1:100 volume per volume.
  3. Cleanse the testing site, usually the volar surface of the forearm or the lateral aspect of the upper arm, with an alcohol swab and allow it to dry completely.
  4. Draw approximately 0.02 to 0.05 mL of each diluted allergenic extract into separate tuberculin syringes equipped with 26-gauge or 27-gauge needles.
  5. Inject the extract superficially into the dermal layer of the skin at a 10 to 15 degree angle to produce a discrete intradermal bleb or wheal of about 2 to 3 millimeters in diameter.
  6. Administer identical intradermal injections of a positive control (histamine) and a negative control (saline or diluent) to serve as baseline references for the patient's skin reactivity.
  7. Observe the patient continuously for 15 to 20 minutes, remaining vigilant for any early signs of systemic allergic reactions or impending anaphylaxis.
  8. Measure and record the maximum diameter of the resulting wheal and the surrounding flare (erythema) for each injection site using a standardized millimeter ruler.
  9. Compare the dimensions of the extract test sites to the positive and negative control sites to interpret the presence and severity of the immediate hypersensitivity reactions.
  10. Document the entire procedure, precise measurements, final clinical interpretations, and formulated treatment plan in the comprehensive medical report.

Coding Guidelines

  • Report CPT code 95024 for each individual intracutaneous (intradermal) test performed. The number of units billed must match the exact number of tests administered.
  • Do not report 95024 for a specific allergen if the percutaneous test (CPT 95004) for that exact same allergen was already strongly positive, as intradermal testing is medically unnecessary in that scenario.
  • The code inherently includes the administration of the test, the clinical interpretation of the results, and the preparation of the final report; do not bill these components separately.
  • Direct supervision by a physician or other qualified healthcare professional is strictly required due to the risk of anaphylaxis. The supervising provider must be immediately available in the office suite.
  • Evaluation and Management (E/M) services (e.g., 99202-99215) should not be billed on the same day as allergy testing unless a significant, separately identifiable E/M service based on complexity or time is provided, which requires modifier 25.
  • Do not use 95024 for delayed hypersensitivity testing; use patch testing codes (e.g., 95044) for contact dermatitis evaluations.
  • If testing includes venom or drugs, ensure the medical record clearly supports the necessity of these specific tests through appropriate clinical documentation and corresponding ICD-10 diagnosis codes.

Associated ICD-10 Codes