[Sinusitis. An illness to be taken seriously].

Sinusitis (which should more accurately be called rhinosinusitis because of regular involvement of the nasal cavities) is one of the most widespread illnesses in Europe and the USA, with considerable socioeconomic burden and an increasing prevalence. From a clinical point of view, a distinction is made between acute, acute recurrent and chronic sinusitis. For the patients affected, sinusitis is associated with irritating to agonizing symptoms, which can have a seriously adverse effect on the quality of life. If complications arise, major risks may be involved affecting the orbits and neurocranium. Rational, evidence-based diagnosis and therapy is therefore absolutely essential. Guidelines may be helpful, particularly since data available on medication-based treatment, especially of the chronic form, are extremely sparse.