We construct a relativistic and unitary approach to 'high' energy pion-and photon-nucleon reactions taking the ฯN, ฯโ, ฯN, ฯN, ฮทN, Kฮ, Kฮฃ final states into account. Our scheme dynamically generates the s-and d-wave nucleon resonances N(1535), N(1650) and N( ) and isobar resonances โ(1620) and โ(1700) in terms of quasi-local interaction vertices. The description of photon-induced processes is based on a generalized vector-meson dominance assumption which directly relates the electromagnetic quasi-local four-point interaction vertices to the corresponding vertices involving the ฯ and ฯ fields. We obtain a satisfactory description of the elastic and inelastic pion-and photon-nucleon scattering data in the channels considered. The resulting s-wave ฯ-and ฯ-nucleon scattering amplitudes are presented. Using these amplitudes we compute the leading density modification of the ฯ and ฯ energy distributions in nuclear matter. We find a repulsive energy shift for the ฯ meson at small nuclear density but predict considerable strength in resonance-hole like ฯ-meson modes. Compared to previous calculations our result for the ฯ-meson spectral function shows a significantly smaller in-medium effect. This reflects a fairly small coupling strength of the N(1520) resonance to the ฯN channel.