H1/H2 blockers
Diphenhydramine
Famotidine
2nd line agents: antidepressants
Doxepin 
Start at 10 mg daily and increase to 10 mg TID 
Avoid if recent MI
Avoid if liver dysfunction
Mirtazapine
15 mg daily 
Consider corticosteroids
methylprednisolone 125mg IV/IM OR prednisone 60mg PO
Diphenhydramine
Famotidine
Doxepin 
Start at 10 mg daily and increase to 10 mg TID 
Avoid if recent MI
Avoid if liver dysfunction
Mirtazapine
15 mg daily 
Start at 10 mg daily and increase to 10 mg TID 
Avoid if recent MI
Avoid if liver dysfunction
15 mg daily 
methylprednisolone 125mg IV/IM OR prednisone 60mg PO
Chronic urticaria
Allergic reaction/urticaria
Cold urticaria
Anaphylaxis
Atopic dermatitis
Angioedema
Contact dermatitis
Anxiety attack