Yellow nail syndrome is a disease of unknown origin, consisting of a triad: nail changes, lymphoedema and respiratory disorders (bronchiectasias, pleural effusion, relapsing pneumonias, bronchitis and sinusi¬tis). A 66-year-old male with long-lasting onychomycosis on the feet suffered from repetitive exacerbations of chronic bronchitis followed by pneumologist since autumn 2003. In February 2004 the dermatologist had begun the treatment of onychomycosis by systemic terbinafine, however the new nail changes appeared also on the nails on the hands during treatment. Laboratory tests showed alternation of various fungal and bac-terial pathogens in the nails. On the basis of the triad of yellow nails, finger lymphoedema and repetitive respiratory infections we made a diagnosis of yellow nail syndrome and the systemic antimycotics were changed for systemic vitamin E in the dose of 400 mg per day. Patient was simultaneously followed by pneumologist. During treatment the finger oedema diminished, the diseased nails began to separate and new nail plates of normál appearance regrew. The syndrome is considered to be rare but probably a lot of cases are misdiagnosed for therapeutically refractory onychomycosis. That is why we bring up a differen-tial diagnosis of this multidisciplinary disease.

        Key words: yellow nail syndrome - differential diagnosis - therapy