Table 3 Recommended Diagnostic Tests in Frequent Urticaria Subtypes
From: A Summary of the New International EAACI/GA1LEN/EDF/WAO Guidelines in Urticaria
Types | Subtypes | Routine Diagnostic Tests (Recommended) | Extended Diagnostic Programme (Suggested) for Identification of Eliciting Factors and for Ruling Out Possible Differential Diagnoses if Indicated |
|---|---|---|---|
Spontaneous urticaria | Acute spontaneous urticarial | None | None |
Chronic spontaneous urticaria | Differential blood count and ESR or CRP omission of suspected drugs(e.g. NSAID) | Test for (i) infectious diseases (e.g. Helicobacter pylon); (ii) type I allergy; (iii) functional autoantibodies; (iv) thyroid hormones and autoantibodies; (v) skin tests including physical tests; (vi) pseudoallergen-free diet for 3 weeks and tryptase, (vii) autologous serum skin test, lesional skin biopsy | |
Physical urticarial | Cold contact urticarial | Cold provocation and threshold test (ice cube, cold water, cold wind) | Differential blood count and ESR/CRP cryoproteins rule out other diseases, especially infections |
Delayed pressure urticaria | Pressure test (0.2-1.5 kg/cm[2] for 10 and 20 minutes) | None | |
Heat contact urticaria | Heat provocation and threshold test (warm water) | None | |
Solar urticaria | UV and visible light of different wave lengths | Rule out other light-induced dermatoses | |
Demographic urticaria/urticaria factitia | Elicit demographism | Differential blood count, ESR/CRP | |
Other urticaria types | Aquagenic urticaria | Wet cloths at body temperature applied for 20 minutes | None |
Cholinergic urticaria | Exercise and hot bath provocation | None | |
Contact urticaria | Prick/patch test read after 20 minutes | None | |
Exercise-induced | According to history exercise test with/without | None | |
anaphylaxis/urticaria | food but not after a hot bath | ||