Patients with<unk>  usually appear flushed. Physical examination of patients with<unk>  is usually remarkable for swollen lips or other areas, wheezing, cyanosis, and low blood pressure. It is vital for the physician to assess cardiac and respiratory symptoms for any compromise as soon as possible. 
The diagnosis is likely when any one of the following criteria is met: 
1. Acute onset with involvement of mucosal tissue, skin, or both and one of the following:
Respiratory compromise
Reduced blood pressure or evidence of end-organ dysfunction
2. Exposure to a likely antigen for the patient followed by two of the following:
Skin involvement
Respiratory compromise
Reduced blood pressure
Gastrointestinal symptoms
3. Exposure to a known allergen to the patient followed by reduced blood pressure
Respiratory compromise
Reduced blood pressure or evidence of end-organ dysfunction
Skin involvement
Respiratory compromise
Reduced blood pressure
Gastrointestinal symptoms
Anaphylaxis physical examination
Heartburn physical examination
DRESS syndrome physical examination
Heat stroke physical examination
Drug allergy physical examination
Allergic conjunctivitis physical examination
Peripheral neuropathy physical examination
Urticaria physical examination