In late November 2007, the administration of the Clermont de l'Oise Interdepartmental Hospital Center reported to health authorities that approximately ten members of its staff had developed irritant-type skin symptoms. An epidemiological investigation, coordinated by Cire Nord, was conducted in conjunction with a clinical assessment carried out by the dermatology department of the Amiens University Hospital. Ineris tested for certain pollutants to verify potential airborne exposure of staff. Finally, environmental comfort parameters (temperature, humidity, air exchange rate) were measured. A total of 42 people reported at least one irritant-type symptom. In the majority of cases, the symptoms described were mild, nonspecific, and transient. None of the hospitalized patients were affected by the incident. In mid-November 2007, the episode escalated sharply following the emergence of two cases presenting with severe dermatitis. Clinical evaluation concluded that these two individuals had two distinct forms of dermatitis, unrelated to the irritative symptoms reported by other staff members. Environmental measurements revealed insufficient air exchange and slightly low humidity. Pollutant measurements ruled out the presence of a specific pollutant in high concentrations. Overall, the characteristics of this phenomenon suggest sick building syndrome. The emotional reaction triggered by the simultaneous occurrence of two cases of severe dermatitis in the same unit likely contributed significantly to the amplification of the phenomenon. (R.A.)