When medical history, physical examination and laboratory tests show that allergies have an important impact on a child’s asthma, skin tests should be taken.The skin tests detect the present of antibodies or reagins which are present not only in blood but also in the skin. The reaction of the antibody the skin with the corresponding antigen applied in the skin tests, causes the release of histamine or histamine-like substance by the tissues, and results in a weal and redness around the test site.Skin tests are done with the extracts of the pollens, dusts and moulds. It is essential that the extracts be prepared methodically and these be active and potent and not old. Skin tests can be done by either of the two techniques:1. Scratch test, and2. Intracutaneous test.Scratch Test. A series of superficial scratches or abrasions about 1/4 cm long are made on the cleansed skin of the arm or the forearm. Care is taken to ensure that scratches do not cause bleeding. A small drop of each of the test substances i.e. different allergy causing allergens, is placed on the child’s forearm. The outermost layer of the skin is gently lifted with a needle tip to let each drop flow in. The procedure is almost painless and therefore can be done on children with ease, without causing any apprehension to the parents. After 15 to 20 minutes, the reactions at the test sites are observed and interpreted on the basis of comparison with a control test. The control test is made with harmless diluent devoid of the allergy priinciple.Intracutaneous Test. These involve the  introduction of about 0.02 ml of each of the sterile allergenic extracts into the skin by a syringe. The reactions resulting from the intracutaneous techniques are generally larger than those obtained with the scratch technique, and the tandard of recording and interpretation vary with each procedure. Intracutaneous tests, if not performed with care, can sometimes cause allergic reactions.Within a few minutes of the test a positive reaction is shown by a small, white, itching bump appearing, which may be surrounded by some reddening of the skin. The intensity of the allergy is related to the size of the lump, but even the most severe reactions in this type of test disappear after half an hour or so, leaving no after effects. Almost every asthmatic child will have at least one or two positive reactions, if not several reactions. Unless the substance under test has also been noticed to cause the child to wheeze regularly, the positive test just shows that he produces harmless allergic antibodies in his blood more easily than usual.*51\260\8*