The national Network of a roblologique (RNSA) surveillance has as mission to unite information on the allergic risk linked to pollens and to mildew from sensors divided on all French territory, and to establish newsletters allowing to define measures of alert, of prevention and of prescript.

Quarantine sensors of pollens and of mildew are divided in France in urban zones, outside houses. These sensors inhale ambient air and cast it on a grip tape; all the particles contained in this inhaled air are so compact es on this band reading of which is daily. Sensors are changed every week.

Clinical information is also gathered on every site thanks to a doctor Sentry, always an allergist, who has a network of correspondents, general practitioners and specialists.

Every week, these doctors fill a questionnaire which allows to assess allergic risk on the site. It allows to measure the prevalency of this or that symptom in given period, does Michel Thibaudon manager of the RNSA explain had more rhinites there? Or of conjunctivitises? Is the cough frequent? The valuation of the level of implemented treatment is also noted. Did the doctors prescribe only of anti7 istaminiques or they had to have recourse to corticoids? These considerations allow to quantify the level of gravity of the met pathology.

Three pollen seasons

All information emanating from sensors and from doctors is collected by RNSA, who establishes allergo-pollen newsletters. They specify pollens in reason and the risk linked to these pollens and to this mildew. The cumul of data and of meteorology is going to allow to predict risk to come. Newsletters are announced to all members of network (a hundred in all France), in DASS and in DRASS, in the Health institute and on the Website (rnsa.asso.fr).

Pollen risk is linked to three big seasons of pollens: the season of trees, from January to the end of May; the season of grasses, from the beginning of May to the end of July; the season of the herbaceous, from July to the end of September. Cypresses being of trees very allergisants, it would be therefore possible to say, they expliq e Michel Thibaudon, that risk is maximum on Mediterranean perimetre, but ilfaut to know that pollens travel on dozens, or even hundreds of kilometres .

Information being transmitted through newsletters, measures can be taken. At preventive level by informing the patients, and at the level of prescripts to put under way or to follow the symptomatic treatments. An example, underlines Mich l Thibaudon: it can be very useful to tell the pediatricians that such period is that of allergic rhinites rather than that of contagious rhinites. And therefore that prescript antibistaminiques will be more efficient than that of antibiotics.

All vegetation is covered with mildew and programme of spores is extremely abundant. There is a very big diversity of mildew, but they were much less studied than pollens; and some are very allergisantes.

Two peaks for mildew

Two peaks are to signal: the first from June 15th till the end of July, and the second of September 15th at the beginning of November. The clinical demonstrations of mildew being relatively close to pollen demonstrations, the doctors have some tendency to link them to a pollinose, and it especially since they have no battery of tests equivalent to that of pollens. The humid regions are theoretically more affected than the dry regions, but here still the wind is very advantageous for displacement. All that concerns mildew follows exactly the same circuit as for pollens; sensors, doctors sentries, RNSA, newsletter, measures of alert.