Contact thermo-optical structure and its application for non-invasive imaging of histamine-induced hyperthermal subcutaneous reaction magnitude in cutaneous allergic reaction, recording device and method of allergic reaction diagnosis
View Patent ↗A passive planar thermo-optical structure for detection of a region of changed temperature on patient's skin is provided. The thermo-optical structure has a layered structure including a transparent film layer, a thermochromic layer, a securing layer, an adhesive layer, and a protective layer. At least one dye in the thermochromic layer is above a temperature threshold range of 31°-37° C., which adopts the first color and keeps it in a temperature range greater than or equal to 0.6° C. A width of this temperature range, in which the color is indefinite, is smaller than 0.3° C. A method of diagnosing allergy using the above-structure is provided. The method includes the steps of stimulation, measurement and comparison. After stimulating three regions of patient's skin, an evaluation of extent of histamine reaction is performed. Then, the extent of histamine reaction in the third region is compared to that in the first and second regions.
1. A method of diagnosing skin allergic reactions induced by in vivo skin prick test (SPT) and skin patch test (PT) and by identification of hyperthermic allergic responses, the method comprising the steps of:
applying respectively on a first region, a second region, and a third region of patient's skin:
a positive control histamine solution having a minimum concentration of 1 mg/ml to obtain a positive control reaction,
a negative control sodium chloride (NaCl) solution having a concentration of 0.9% to obtain a neutral or negative control reaction, and
a standarized testing allergen solution to induce allergic skin responses to evaluate allergic reactions;
measuring hyperthermic reactions in the first, second and third regions by identification of hyperthermic areas displayed on a screen of a planar thermosensitive detector; and
comparing a size of the positive control reaction (histamine-induced hyperthermia in the first region) with a size of the neutral or negative control reaction (sodium chloride-induced hyperthermia in the second region) and a size of the allergic reactions (allergen-induced hyperthermia in the third region),
wherein the comparing step is performed based upon an extent of color images displayed, in the measuring step, on the screen of the planar thermosensitive detector, said displayed color images being relevant to the hyperthermic areas revealed over patient's skin in the first, second and third regions.
2. The method according to claim 1 , wherein the measuring step is performed automatically by means of a recording device.
3. The method according to claim 1 , wherein the applying step is performed by puncturing the patient's skin with a needle having a substance applied thereon.
4. The method according to claim 1 , wherein the applying step is performed by application of a substance on the skin.
5. The method according to claim 1 , wherein in the measuring step a greatest dimension S T of the allergen-induced hyperthermia in the third region, a greatest dimension S H of the histamine-induced hyperthermia in the first region and a greatest dimension S N of the sodium chloride-induced hyperthermia in the second region are associated with their relevant color changes of a thermochromic layer of the planar thermosensitive detector.
6. The method according to claim 5 , wherein in the comparing step the hyperthermic allergic reaction is deemed positive (the test substance is an allergen) if a result of following operation
S
T
-
S
N
S
H
-
S
N
is greater than or equal to 1.