[Value of skin prick test and atopy patch test in mite-induced respiratory allergy and/or atopic eczema/dermatitis syndrome].

AIM

The atopy patch test (APT) was introduced to assess sensitization to inhalant allergens in patients with atopic/eczema dermatitis syndrome (AEDS), but its diagnostic role in subjects with respiratory allergy is scantly investigated. We sought to evaluate the response to APT and to skin prick tests (SPT) with mite extracts in subjects with persistent respiratory symptoms (rhinoconjunctivitis, rhinosinusitis, asthma), with AEDS, and with both the diseases.

METHODS

Eighty-nine patients were included in the study, 75 (84.3%) children and 14 (15.7%) adults, 54 (60.7%) males and 35 (39.3%) females (median age 5.4 years). They were divided in 3 groups, respectively formed by 47 (mean age 12.3+/-11.6 years), 15 (mean age 2.2+/-2.5 years), and 27 (mean age 6.2+/-6.3 years) subjects, according to the presence of only respiratory symptoms, only AEDS, or both, and underwent to usual SPT with mite extracts and to APTs done by mite extract in Finn chambers and removed after 48 hours, with readings after 20 minutes and 24 hours.

RESULTS

Of the 89 patients, 24 showed a positive SPT and 69 a positive APT; in 17 both SPT and APT were positive, while 13 were negative to the 2 tests. The APT was more frequently positive than SPT not only in the 2 groups with AEDS -- 32/42 (86.5%) vs 8/42 (21.6%) -- but also in the group with only respiratory symptoms -- 37/47 (78.7%) vs 16/47 (34%).

CONCLUSION

These results confirm the high value of APT in patients with mite-induced AEDS and suggest that its routine use might improve also the diagnosis of respiratory allergy to house dust mites.