What is the procedure for an intradermal (within the skin) progesterone skin test?

Intradermal Progesterone Skin Test Procedure

The intradermal progesterone skin test procedure involves injecting 0.02 to 0.05 ml of a dilute progesterone solution intradermally on the forearm or back, with results read after 15-30 minutes, looking for a wheal 3mm or greater than the negative control with accompanying erythema. 1

Preparation and Materials

• Required materials:

  • Progesterone solution (aqueous preparation)
  • Histamine solution (positive control)
  • Physiological saline (negative control)
  • 1ml syringes with fine needles (25-27G)
  • Alcohol swabs
  • Ruler or caliper for measuring reactions

• Patient preparation:

  • Discontinue antihistamines and medications with antihistamine activity for several days before testing 1
  • No need to discontinue oral or inhaled steroids 1
  • Document all medications taken within the past week 1

Testing Procedure

1. Select testing site:

   • Typically performed on the volar surface of the forearm or back 1

2. Prepare controls:

   • Apply histamine solution as positive control
   • Apply physiological saline as negative control 1

3. Intradermal injection technique:

   • Clean the skin with alcohol and allow to dry
   • Draw up 0.05-0.07 ml of progesterone solution in the syringe
   • Expel excess fluid and air bubbles to obtain exactly 0.02 ml 1
   • Insert needle at a 10-15° angle just beneath the epidermis
   • Inject 0.02-0.05 ml of progesterone solution to create a 3-5 mm bleb 1

4. Reading and interpretation:

   • Observe the injection site after 15-30 minutes 1
   • Measure both wheal and erythema (flare) reactions
   • Positive result criteria: Wheal ≥3 mm larger than negative control with ≥5 mm flare 1
   • Document measurements of wheal and erythema for both allergen and controls 1

Special Considerations

• Safety precautions:

  • Testing should be performed by trained personnel experienced in skin testing 1
  • Emergency equipment must be available to treat potential anaphylaxis 1
  • Maximum concentration for intradermal progesterone should be carefully controlled to avoid skin reactions 1

• Diagnostic reliability:

  • Recent research raises concerns about the specificity of intradermal progesterone testing, as healthy controls without symptoms may also develop positive skin reactions 2
  • Consider the test results in context with clinical symptoms, particularly cyclical manifestations related to menstrual cycle 3, 4

Clinical Applications

• Primary indication:

  • Diagnosis of autoimmune progesterone dermatitis (APD), a rare condition characterized by cyclical skin eruptions occurring during the luteal phase of the menstrual cycle 2, 3

• Alternative testing approaches:

  • In cases where aqueous progesterone solution is unavailable, vaginal progesterone provocation has been successfully used for diagnosis 5
  • Autologous serum skin testing using sera from estrogenic and luteal phases may be helpful in some cases 6

• Interpretation pitfalls:

  • False positives may occur, as demonstrated by positive reactions in asymptomatic controls 2
  • False negatives may occur if testing is performed during inappropriate timing in relation to symptoms
  • Consider as part of a diagnostic algorithm rather than sole diagnostic criterion 4

When evaluating suspected progesterone hypersensitivity, the intradermal test should be interpreted alongside the patient's clinical history, particularly noting the cyclical nature of symptoms in relation to the menstrual cycle.