The document provides instructions for performing patch testing to identify contact allergies. It states that medications should be stopped before testing if possible. The back or upper arm are recommended test sites, with allergen patches applied for 48 hours and read at 1, 48, and optionally 120 hours. Positive reactions to multiple unrelated allergens indicates polysensitization. Standard allergen series include the European, British, North American, and Indian standard series. Patch tests can also be performed with UV irradiation or as open, semi-open, or use tests.

1. DR.SABHA TALIB
NEAZEE

2. To elicit an immune response by
challenging already sensiitized
person to defined amount of
allergen and assessing the degree of
response.

4.  Stop all anti immunosuppressants if feasible.
 Systemic agents before 3 months.
 Biologics before 6 months.
 Topical corticosteroids before 2 weeks.
 Prednisolone < 15mg according to ROOK’S
TEXTBOOK OF DERMATOLOGY and
prednisolone < 10mg according to BRITISH
ASSOCIATION OF DERMATOLOGISTS can be
continued.
 Discontinuation of antihistamines is desirable
before 48 hours.

5.  Prohibition of wetting the back.
 Prohibition of performing activities that
increase sweating.
 Probable local symptoms such as itching .
 Prohibition of exposing themselves to UVR
upto fifteen days prior to testing.

6.  Prohibition of wetting the back.
 Prohibition of performing activities that
increase sweating.
 Probable local symptoms such as itching .
 Prohibition of exposing themselves to UVR
upto fifteen days prior to testing.

7.  Test site-Back
Lateral aspect of upper arm
 Exposure time- 48 hour application time with
readings taken 1 hour after removal and then
48 hours later. Day 2 and day 4.
 If only 1 patch test reading- day 4.
 3rd reading- 5 to 7 days if possible.

14.  Positive reaction to more than five non
related substances.
 Poly sensitization.
 Repeat testing of selected allergens two
months later.

16.  Compound allergy-Positive allergic patch test
is seen to a finished product but tests with
ingredients are negative.
 Quenching – inhibition of response.

17.  European environmental and contact
dermtitis research group,EECDRG- 28
allergens.
 British society for cutaneous allergy, BSCA-
39 allergens
 North american contact dermatitis group,
NACDG- 65 allergens.
 Indian standard series- 20 allergens.

18.  The allergens are tested in duplicate on back
and irradiated with UV light( most often UV-A
5j/cm2
 1st reading- immediately post irradiation.
 2nd reading- 2 days post irradiation.

19.  Open- allergen is applied uncovered on the
upperarm or upperback twicedaily for 2 days
 Semiopen- direct application of liquid with a
cotton tip applicator. 1 cm2. after complete
evaporation, test site is covered with acrylic
tape.
 Reading day 2 AND DAY 4.

20.  0.1ml of test material is applied twice daily
to flexor aspect of forearm. 25 cm2.
 1st reading – after 1 week.
 May be performed for upto 21 days.