Table 2.

Features of selected randomized controlled trials discussed in this review.

	Approach	Subjects	Regimen	Reported significant (p<0.05 or less) improvement in the actively treated group vs. control group	Reported adverse reactions
Alvarez-Cuesta E et al. 199476	SCIT, RCT, DB, PC, cat allergy	28, aged 15-28 yrs, A with RC	Cat dander extract, 1 yr	Medication-symptoms score, skin prick test, conjunctival provocation, allergen bronchoprovocation	Local reaction in 7 subjects and mild systemic reactions in 3 subjects in the actively treated group
Alvarez-Cuesta E et al. 200780	SLIT, RCT, DB, PC, cat allergy	50, mean age 27 yrs, RC with/without A	Cat dander extract, 1 yr	Total and nasal symptoms scores, PEF, skin test reactivity	No local or systemic reactions
Haugaard L et al. 199283	SCIT, RCT, DB, PC, cat and/or dog allergy	24, aged 13–48 yrs, A	Cat and/or dog dander extract, 5 mo	Symptoms of cat-allergic subjects on cat exposure	Local reactions in about 25% of all injections, some systemic reactions in both groups, 1 severe asthma reaction and 1 anaphylactic reaction in the actively treated group
Nelson HS et al. 199379	SLIT, RCT, DB, PC, cat allergy	41, aged 18-74 yrs, RC with/without A	Cat hair and epithelium extract, 105 d	Not observed	Similar number of mild reactions in both groups
Ohman JL et al. 198484	SCIT, RCT, DB, PC, cat allergy	17, aged 22-48 yrs, A	Cat pelt extract, 16 wk	Skin test reactivity, pulmonary symptoms score on cat exposure, subjective allergic symptoms, allergen-specific IgG	Large local reactions in 2 subjects and systemic reactions in 4 subjects in the actively treated group, systemic reactions in 1 subject in the placebo group, all mild
Sundin B et al. 198685	SCIT, RCT, DB, PC, cat or dog allergy	41, aged 8-47 yrs, A	Cat or dog dander extract, 1 yr	Allergen bronchoprovocation	Systemic reactions in all 12 children at high allergen doses (build-up in rush IT), all mild, otherwise a few mild systemic or local reactions
Valovirta E et al. 198481, 198682	SCIT, RCT, DB, PC, dog allergy	27, aged 5-18 yrs, A	Dog dander and hair extract, 1 yr	Conjunctival provocation, skin test reactivity, allergen-specific IgG	No significant difference in mild local reactions between the groups
Van Metre TE et al. 198886	SCIT, RCT, DB, PC, cat allegy	22, aged 21-52 yrs, A	Cat hair and dander extract, 1 yr	Allergen bronchoprovocation, skin test reactivity, allergen-specific IgG	Mild systemic reactions in 2 subjects and large local reactions in 6 subjects in the actively treated group
Varney VA et al. 199777	SCIT, RCT, DB, PC, cat allergy	28, aged 19-50 yrs, RC with A	Cat dander extract, 3 mo	Asthma symptom score, allergen bronchoprovocation	6 large local reactions in both groups, 3 mild systemic reactions in the actively treated group and 2 in the control group

SCIT - subcutaneous allergen immunotherapy, RCT - randomized controlled trial, DB - double-blind, PC - placebo-controlled, A - asthma, RC - rhinoconjunctivitis, SLIT - sublingual allergen immunotherapy