405:
Prevalence of skin sensitivity to temperate and subtropical grasses in patients with seasonal allergic rhinitis in Bahía Blanca, Argentina.
Sunday, March 4, 2018
South Hall A2 (Convention Center)
Ivan Cherrez-Ojeda, German Dario Ramon, MD, Laura B. Barrionuevo, Nadia Arango, Maria A. Long, Valentina Viego
RATIONALE: There are few studies of cutaneous sensitivity to gramineae in our region. Mostly of them use allergens of foreign species. The study aims to estimate the prevalence of skin sensitivity to widespread grasses in our region.

METHODS: This is a retrospective observational study of 894 patients with seasonal allergic rhinitis. Patients were studied using skin tests with pollens extracts from Pooideae, Chloridoideae and Panicoideae grass species.

RESULTS: The prevalence of positive reaction to pollen from Pooideae subfamily was 86.8% (IC: 84.4%-88.9%). In turn, prevalence of allergy to Panicoideae subfamily pollens was 69.6% (IC: 66.5%-72.5%) and positive reaction to Chloridoideae subfamily reach 48.1% (IC: 44.8%-54.1%). Cochran test suggests that prevalence in those three groups is different (χ2=319.11, p<0.01). When comparing just the groups of allergens from Pooideae and Panicoideae differences are also significant (χ2=71.43, p<0.01). In particular, 52.5% (IC: 49.2%-55.7%) of patients were allergic to Paspalum notatum. Regarding cross-reactivity between subfamilies, we find a no cross-correlation between Pooideae and Panicoideae (χ2=2.197, p=0.138).

CONCLUSIONS: In Bahia Blanca, patients with seasonal rhinitis are sensitive to Pooideae, Chloridoideae and Panicoideae. Paspalum notatum, belonging to Panicoideae, has a significant prevalence, high reactivity and low cross-reactivity within the group of species studied. This last species is relevant because it is a native grass from the Northwest region of our country, Paraguay and the South of Brazil.