| Disorder | Inciting trigger(s) | Diagnostic test |
| Symptomatic dermographism (urticaria factitia) | Firm stroking, scratching, pressure | Moderate stroking of the skin with a blunt, smooth object (eg, closed ballpoint pen tip, wooden tongue depressor) or dermographometer. |
| Delayed-pressure urticaria/angioedema | Application of pressure 0.5 to 12 hours before onset of symptoms | Sling with weights placed over arm or shoulder for 15 minutes (7 kg weight on 3 cm wide shoulder strap). Patient reports symptoms over next 24 hours. Dermographometers are used in research (100 grams/mm2 for 70 seconds). |
| Cholinergic urticaria | Elevation of body temperature (exercise, hot water, strong emotion, hot or spicy food) | Exercise using a machine (stationary bicycle or treadmill) to the point of sweating. Then, continue for 15 minutes. If this test is positive, then passive heating of one/both arms in 42°C warm water bath to cause increase in body temperature of ≥1°C. Some patients may react to skin testing with own sweat. |
| Cold contact urticaria | Exposure of skin to cold air, cold liquids, or cold objects | Ice cube test - Melting ice cube in thin plastic bag for 5 minutes. TempTest where available to determine patient's threshold. |
| Heat contact urticaria | Warm object in direct contact with affected skin | Application of test tube containing 45°C water or metal cylinder heated to 45°C to skin for 5 minutes. |
| Exercise-induced urticaria/anaphylaxis | Physical exertion | Treadmill testing. |
| Aquagenic urticaria | Skin contact with water of any temperature Salinity of water important in some cases | Application of 35°C water in compress to upper body for 30 to 40 minutes. |
| Solar urticaria | Exposure of skin to sunlight (triggering wavelengths vary) | Exposure of normally covered skin to UVA (6 J/cm2), UVB (60 mJ/cm2), and visible light (projector). |
| Vibratory urticaria/angioedema | Lawn mowing, riding a motorcycle, horseback riding, mountain biking, exposure to vibrating machinery, holding some steering wheels | Vortex mixer is held against skin for 10 minutes. |
