Table 7. Comparison of EAACI classification and WAO classification of systemic reactions in allergen immunotherapy.
| Grade | EAACI (74) classification of systemic reactions | WAO classification of systemic reactions (269) |
|---|---|---|
| Grade 0 | No symptoms or nonspecific symptoms | – |
| Grade I | Mild systemic reactions | Symptoms/signs present in single organ/system |
| Localized urticaria, rhinitis or mild asthma (PF <20% decrease from baseline) | (I) Cutaneous: generalized pruritus, urticarial, flushing, sensation of heat or warmth, angioedema | |
| (II) Nose or throat: sneezing, watery rhinorrhea, nasal itching, and nasal obstruction; itchy throat | ||
| (III) Conjunctival: erythema, itching, tearing | ||
| (IV) Other symptoms: nausea, metallic taste, or headache | ||
| Grade II | Moderate systemic reactions | Symptoms/signs present in more than 1 organ/system |
| Slow onset (>15 min) of generalized urticaria and/or moderate asthma (PF <40% decrease from baseline) | (I) Lower respiratory: asthma, cough, wheezing, chest tightness, shortness of breath (less than 40% PEF or FEV1 decrease, relieved by an inhaled bronchodilator) | |
| (II) Gastrointestinal: abdominal cramps, vomiting, or diarrhea | ||
| (III) Other symptoms: uterine cramps | ||
| Grade III | Severe (non-life-threatening) systemic reactions | Symptoms/signs present in single organ/system |
| Rapid onset (<15 min) of generalized urticaria, angioedema, or severe asthma (PF >40% decrease from baseline) | (I) Lower respiratory: asthma (40% PEF or FEV1 decrease), not responding to an inhaled bronchodilator | |
| (II) Upper respiratory: laryngeal, uvula, or tongue edema with or without stridor, hoarseness, inspiratory dyspnea, shortness of breath | ||
| Grade IV | Anaphylactic shock | Symptoms/signs present in more than 1 organ/system |
| Immediately evoked reactions of itching, flushing, erythema, generalized urticaria, stridor (angioedema), immediate asthma, hypotension etc. | (I) Lower or upper respiratory: respiratory failure with or without loss of consciousness | |
| (II) Cardiovascular: hypotension with or without loss of consciousness | ||
| Grade V | Death |
EAACI, the European Academy of Allergy and Clinical Immunology; WAO, World Allergy Organization; PEF, peak expiratory flow; FEV1, forced expiratory volume in one second.