Table E1.

Hypersensitivity reaction definitions and method of identification in the electronic health record

Reaction name	Coded text	Free text keywords
Immediate Hypersensitivity Reactions
Itching	Itching	Itching, itching eyes, itching in mouth, itching of eyes
Hives	Hives	Hives, urticaria
Respiratory	Bronchospasm; bronchospasm or wheezing; shortness of breath; wheezing	Bronchospasm; wheezing; shortness of breath, breathing difficulty, respiratory distress; airway closure, airway constriction, apnea; asthma, asthma attack, asthma exacerbation, asthma flare, asthmatic reaction
Angioedema	Angioedema; swelling	Angioedema, swelling, throat edema, tongue edema, lip edema; lip swell, swollen eye(s), and swollen face
Anaphylaxis	Anaphylaxis; hypotension	Anaphylaxis, anaphylactic reaction, anaphylactic shock; asystole, cardiac arrest, cardiopulmonary arrest; hypotension, hypotensive, low blood pressure; shock
Delayed Hypersensitivity Reactions
Rash	Hives or other rash; rash	Rash, allergic contact dermatitis, allergic dermatitis, atopic dermatitis, blistering rash, rash around mouth, rash in mouth, skin eruption, skin eruptions
Fixed drug Eruption	N/A	Fixed drug eruption, fixed drug reaction
Erythema nodosum	N/A	E nodosum, erythema nodosum
Serum sickness	N/A	Serum reaction, serum sickness
Pneumonitis	N/A	Allergic pneumonitis, hypersensitivity pneumonia, hypersensitivity pneumonitis, pneumonitis
Acute interstitial nephritis	N/A	Acute interstitial nephritis, AIN, allergic interstitial nephritis, interstitial nephritis
Severe cutaneous adverse reaction	N/A	Acute generalized exanthematous pustulosis; DRESS, drug reaction with eosinophilia and systemic symptoms; E multiforme, erythema multiforme; SJS, Steven Johnson syndrome; TEN, toxic epidermal necrolysis; desquamation, severe skin reaction

N/A: no coded entry available for these reactions in electronic health record at time of data collection