#1 Clinical Trials Search in Europe

Sensitivity and specificity of Lepidoglyphus destructor extract, sodium chloride and histamine dihydrochloride in skin prick test for Lepidoglyphus destructor allergy patients

3 1 1

What is this study about?

The study looks at people who have Allergy to Lepidoglyphus destructor. It evaluates a diagnostic preparation containing lepidoglyphus destructor extract. During the skin test, two drops of the extract at different strengths are placed on the skin and compared with a drop of sodium chloride (a harmless salt solution used as a negative control) and a drop of histamine dihydrochloride (a substance that reliably causes a small reaction and is used as a positive control). The purpose of the study is to determine the sensitivity and specificity of the allergen extract, meaning how well the test identifies true allergic reactions and how well it avoids false positives.

Participants will undergo a single prick test session where the drops are applied, and the size of the raised bump (called a wheal) is measured in square millimeters. A larger wheal indicates a stronger reaction. Safety is checked by watching for any uncomfortable feelings at the test site or broader symptoms, which are recorded as adverse events. The study also uses the ALEX technique to profile the allergen, which helps to understand which specific proteins cause the reaction. The overall process takes a short visit, and the results will help choose the best concentration of the extract for future diagnostic use.

1 first clinic visit

after joining the study, attend the designated clinic on the scheduled date.

the visit includes the performance of a skin prick test to evaluate allergy to lepidoglyphus destructor.

2 skin preparation

the skin on the forearm is cleaned with an alcohol swab.

small marks are placed to identify the sites for each solution.

3 application of test solutions

at each marked site, 2 drops (2 gtt) of the following solutions are placed:

  • negative control: sodium chloride solution, cutaneous use
  • test extract: lepidoglyphus destructor extract 450 µg/mL, cutaneous use
  • positive control: histamine dihydrochloride, cutaneous use

all three solutions are applied only once during this visit.

4 measurement of wheal areas

after a brief waiting period, the raised skin areas (wheals) produced by each drop are measured in square millimeters (mm²).

the measurements are recorded as the primary outcome of the study.

5 observation for safety

the patient is observed for any immediate adverse event, such as redness, swelling, or systemic reactions.

any reaction is documented and, if necessary, appropriate medication is administered.

6 follow‑up assessment

the patient may be contacted after the visit to confirm that no delayed reactions have occurred.

all safety information is entered into the study database.

Who Can Join the Study?

  • You must sign and date the informed consent form (a paper that shows you agree to join the study).
  • Your blood test must show a Specific IgE level higher than 0.35 kU/L to the whole extract of L. destructor (IgE is an antibody that indicates allergy; kU/L is a unit of measurement).
  • Your prick test must be negative for L. destructor, meaning the raised bump (wheal) is less than 3 mm across.
  • Your Specific IgE level must be lower than 0.35 kU/L to an extract of L. destructor (shows no allergy).
  • You must have a positive clinical history of inhalant allergy (such as hay fever, eye irritation, or asthma) to other perennial allergens or pollens, but not to L. destructor.
  • You must be between 12 and 70 years old; both men and women can join.
  • Your prick test with the positive control (histamine dihydrochloride at 10 mg/mL) must create a wheal at least 3 mm wide (shows the skin reacts normally).
  • Your prick test with the negative control must create a wheal smaller than 3 mm (shows no reaction to the control).
  • If you are a woman who can become pregnant, you must have a negative urine pregnancy test and tell us the date of your last menstrual period when you join.
  • Women who can become pregnant must agree to use a highly effective contraception method during the study and for 72 hours after the last dose (examples: combined hormonal pills, patches, injections, implants, intrauterine device (IUD), sterilized partner, or sexual abstinence).
  • You must have a positive clinical history of inhalant allergy (such as hay fever, eye irritation, or asthma) to L. destructor.
  • Your prick test to L. destructor must be positive, meaning the wheal is 3 mm or larger.

Who Cannot Join the Study?

  • People who have active hives, severe skin that reacts to light scratching (dermographism), severe eczema (atopic dermatitis), sunburn, eczema, or psoriasis on the spot where the skin test will be done cannot join because these skin problems can give false‑positive results.
  • Anyone who knows they are allergic to phenol, a chemical sometimes used in medicines, must be excluded.
  • Women who are pregnant or are breastfeeding are not allowed to participate.
  • People who have received allergy shots (called immunotherapy) in the past five years, or who are currently using a product containing the L. destructor allergen, cannot be included.
  • Individuals who have strong symptoms of runny nose/itchy eyes (rhinoconjunctivitis) or asthma (bronchial asthma) and cannot stop taking their regular allergy medicine (systemic antihistamines) are excluded.
  • Anyone who previously had a serious bad reaction during a diagnostic skin prick test must not take part.
  • People with an active viral infection such as cold sores (herpes simplex) or shingles (herpes zoster) on the area where the skin test will be performed are excluded.
  • Anyone who is currently very ill or unstable (for example, having an asthma attack, fever, or other acute illness) cannot be enrolled.
  • People with a severe mental health condition (psychiatric disorder) are not eligible.
  • Those who are taking beta‑blocker medications, which affect heart rate and blood pressure, must be excluded.
  • Anyone using medicines that can change the skin’s reaction, such as allergy‑blocking drugs (antihistamines), cannot join the study.
  • People who have a medical condition that makes the use of adrenaline unsafe (for example, overactive thyroid hyperthyroidism, high blood pressure hypertension, or heart disease) are not allowed to participate.

Where you can join this trial?

Verified and Recommended Sites

No sites found in this category

Verified Sites

No sites found in this category

Other Sites

Site Name City Country Status
Hgumjtbf Uekxleksvktjz Lyjzg Akuzyaw Lugo Spain

Want to learn more about this study or check if you can participate? Contact us.

Trial status

Country Status Recruitment Start
Spain Spain
Not yet recruiting
13.06.2026

Trial locations

Investigated Drugs:

Skin Prick Test Negative control
This is a simple salt solution (sodium chloride) that is placed on the skin during the prick test. It does not contain any allergen, so it should not cause a reaction. It is used as a baseline to show what a negative (no‑reaction) result looks like, helping doctors see the difference between a true allergic response and a normal skin response.

Lepidoglyphus destructor extract
This is a liquid made from proteins taken from the dust mite *Lepidoglyphus destructor*. Small drops of this extract are pricked into the skin to see if a person’s immune system reacts. If a red, itchy bump appears, it indicates that the person is allergic to this mite. The study is testing different strengths of this extract to find the most accurate concentration for diagnosing allergies.

Skin Prick Test Positive control
This solution contains histamine, a substance that reliably causes a small skin reaction. It is applied in the same way as the allergen extract. The reaction to histamine confirms that the skin test is working correctly and that the person’s skin can react, providing a comparison point for interpreting the results of the allergen extract.

Allergy to Lepidoglyphus destructor – An allergy to Lepidoglyphus destructor is a hypersensitive reaction of the immune system to proteins from this house dust mite. When a person who is sensitized comes into contact with the mite’s particles, the skin may develop redness, swelling, and a raised bump. Repeated exposure can cause the reaction to become larger and last longer. Over time, the skin may become more reactive, showing bigger wheals with each encounter. The condition is characterized by a pattern of recurring skin responses whenever the allergen is present.

Trial ID:
2025-523426-40-00
Protocol code:
M603-SSP-081
Trial Phase:
Therapeutic confirmatory (Phase III)

Other Trials to Consider

  • Skin Prick Test Diagnostic Accuracy Study in Patients with Dermatophagoides pteronyssinus and Dermatophagoides farinae Allergy Using Dermatophagoides pteronyssinus Extract and Dermatophagoides farinae Extract

    Not yet recruiting

    3 1 1
    Investigated Drugs:
    Spain

  • Study of Blomia tropicalis allergen extract skin prick test compared to histamine in patients allergic to Blomia tropicalis mites

    Not recruiting

    2 1 1
    Investigated Drugs:
    Spain