Consider discharge after 4-6 hrs observation  if there is no airway edema and patient improves or swelling remains isolated to face and lips only
24 hrs obs if epinephrine given
Ishoo Staging may predict severity of disease to help stratify disposition. It is based on retrospective study
Angioedema
Allergic reaction/urticaria
Lymphedema
Anaphylaxis
Lymphangitis
Cyanosis
Anxiety attack
Asthma exacerbation