Table 4 Main provocations tests used for diagnosis of inducible urticaria
Kind of urticaria | Test site | Execution method | Reading time | Positive responsea |
|---|---|---|---|---|
Cold urticaria | Volar surface of the forearm | Contact with a ice cube in a thin plastic bag for 5 min | 10′ | Localized wheal |
Heat urticaria | Volar surface of the forearm | Contact with a cylindrical container filled with hot water for 5 min | 10′ | Localized wheal |
Sunlight urticaria | Buttocks | Irradiation with 6 J/cm2 of UVA and 60 mJ/cm2 of UVB | 10′ | Localized wheal |
Vibratory angioedema | Volar surface of the forearm | Contact with a flat surface placed on a laboratory vortex at a speed between 780 and 1380 rpm (average, 1000 rpm) for 5 min | 10′ | Changes in the circumference of the forearm in 3 points (wrist, central part of the forearm and proximity of the elbow) before and after the stimulus |
Colinergic urticaria | Physical exercise (stationary bike or treadmill) until sweating or until the appearance of skin symptoms | Immediate and after 10′ | Widespread small wheals | |
Aquagenic urticaria | Side surface of the neck Upper part of the back | Contact with tablets soaked in warm water for up to 40 min for 5 min | Immediate and after 10′ | Localized small wheals |
Contact urticariab | Volar surface of the forearm | Contact with the suspected agent for 30′ (open test) If negative, patch test scratch patch test prick test specific IgE in serum | Immediate and up to 60′ | Localized wheal |