Table 2.

Summary of Literature on CIRS Treatment: Study Design, Evidence Levels, and Treatment Outcomes

Study	Evidence pyramid	# of subjects	Type of treatment assessed
Shoemaker17	Level II	8	RCT cholestyramine–successful
Shoemaker and House11	Level II	13	RCT cholestyramine–successful
McMahon et al.18	Level IV	68/23	Case/control–successful
Rea19	Level IV	100	Antigen intradermal treatments–lack of objective data
Shoemaker and House11	Level IV	28	Case time series cholestyramine–successful
Ryan and Shoemaker20	Level IV	14	Case time series vasoactive intestinal peptide–successful
Shoemaker and House21	Level IV	21	Case time series cholestyramine–successful
Shoemaker et al.22	Level IV	156/111	Case/control cholestyramine–successful
Shoemaker et al.23	Level IV	20	Open-label trial vasoactive intestinal peptide–successful
Shoemaker et al.24	Level IV	35/4	Open- label trial vasoactive intestinal peptide–improvement with VIP
Hope25	Level V	Review	Mentions cholestyramine–no data
Gunn et al.26	Level VI	Case	Successful treatment with cholestyramine and vasoactive intestinal peptide
Shoemaker27	Level VI	Case	Successful treatment with cholestyramine–one case
Shoemaker and Hudnell7	Level VI	Cases	Successful treatment with cholestyramine–five cases