Prick test

The usual diagnostic methods, both skin tests and specific IgE with whole Anisakis extract, have a good sensitivity but a low specificity to such a degree that in 22% of blood donors specific IgE to the parasite is detected [40] and at least 20% of patients with acute urticaria have positive skin prick tests with whole Anisakis extract [41 ]. As for BAT with whole Anisakis extract, Gonzalez-Munoz et al. [42] report a sensitivity of 96% with a specificity of 96%, which are clearly higher values than those from specific IgE. 

Does skin prick test reactivity to purified allergens 64 correlate with clinical severity of peanut allergy ... 

Van der Veen MJ. Mulder M. Witteman AM. van Ree R. Aalberse RC. Jansen HM. van der Zee JS False-positive skin prick test responses to commercially available dog dander extracts caused by contamination with house dust mite (Dermatophagoides pteronyssimus) allergens. J Allergy Clin Immunol 1996 98 1028-1034... 

The further allergologic workup is recommended to be performed between 2 and 6 months after the reaction (table 3) [13]. A skin prick test should be performed with undiluted RCM. Afterwards, IDTs with RCM (300-320 mg/ml) diluted 10-fold in sterile saline and reading after 20 min are recommended [13]. As cross-reactivity is frequent, a panel of several different RCM should be tested in an attempt to find a skin test-negative product, which might be tolerated in future RCM examinations. 

True IgE-mediated anaphylactic reactions to LAs are extremely rare [11-13]. Only single cases have been reported in the literature with positive prick tests [ 14,15]. A case of a positive open patch test in a patient suffering from contact urticaria after topical application of lidocaine, pilocaine mixture (Emla cream) might represent a true IgE-mediated allergy [16]. The maj ority of immediate-type reactions are non-immune in nature. 

In a study performed by Ruzicka et al. [23], 104 patients with positive patch tests to LAs and a history of contact dermatitis were tested with LA in a prick test and in an intradermal setting. All prick tests remained negative. There were 9 persons positive for procaine in the intradermal test and 3 positive for butanilicaine. There was no correlation to history in the patients with skin tests and no correlation between patch test results and results of the intradermal test [23]. 

Skin Test. Usually a battery of LAs is tested in the skin-prick test which is almost always negative. Then the intradermal test is performed with a 1 10 dilution of the substances. Undiluted LA preparations may commonly lead to false-positive reactions [30-32] in a rather high percentage of patients. 

If the prick test is non-reactive, proceed to the intradermal test. 

The older test is the pin prick test where a small quantity of the antigen is placed under the skin. If there is an allergic reaction a wheal and flare, i.e. a hive, will appear. The pin prick test is not suitable for those who undergo anaphylactic shock. 

In another Spanish study, Crespo et al. (1995) evaluated 355 children on the basis of clinical history, skin prick tests (SPTs), and specific serum IgE to mollusks. Allergies to molluscan shellfish were noted in 10 of these children or 2.8%. However, mollusks caused 1.6% of 608 allergic reactions among this group of children. 

Clearly, some individuals with molluscan shellfish allergy are reactive to all species of molluscan shellfish. Cross-reactivity has been established by clinical history, challenge trials (in a few instances), skin prick testing, and IgE-binding studies. Most clinical studies of cross-reactivity have been limited to a few species often within one class of molluscan shellfish. However, the totality of the evidence indicates that individuals with documented reactivity to one molluscan species and evidence of IgE against that species should be counseled to avoid other molluscan shellfish species. This recommendation is especially prudent for the individual classes of molluscan shellfish gastropods, bivalves, and cephalopods. 

Eberlein-Konig, B., F. Rueff, and B. SI091 Przybilla. Generalized urticaria caused by sesame seeds with negative prick test result and without demonstrable specific IgE antibodies. J Allergy Clin SI092 Immunol 1995 94(4) 560-561. 

Allergenic effect. A food industry worker developed asthma in inhalation of dust from spices. Skin prick test from ginger was strongly positive. With radioallergosorbent... 

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