Table 3. Relevant investigations for urticaria.
Classification of urticaria/investigation | CBC | ESR or CRP | TA/TFT ANA | IgE | ASST | C4 | Skin biopsy | Physical challenge |
---|---|---|---|---|---|---|---|---|
Acute urticaria | - | - | - | + | - | - | - | - |
Chronic spontaneous urticaria | + | + | + | - | - | + | - | - |
Inducible urticaria | - | - | - | - | - | - | - | + |
Contact urticaria | - | - | - | + | - | - | - | - |
Angio-edema without wheals | - | - | - | - | - | + | - | - |
Urticarial vasculitis | + | + | - | - | - | + | + | - |
Autoinflammatory syndrome | + | + | - | - | - | - | - | - |
Modified from Grattan, et al. Br J Dermatol 2007;157:1116-2325), with permission of Wiley & Sons Inc.
CBC, complete blood count; ESR, erythrocyte sedimentation rate: CRP, C-reactive protein; TA, thyroid antibody; TFT, thyroid function test; ANA, antinuclear antibody; ASST, autologous serum skin test.