In this study we report on functional characteristics of pustule as well as blood polymorphonuclear neutrophils (PMN) in patient suffering from relapsing bullous staphyloderma. Large numbers of viable PMN from newly formed pustules as well as from the peripheral blood were investigated. During the course of disease chemotactic migration, enzyme degranulation, superoxide‐anion generation and leukotriene B4production were determined simultaneously.The results revealed C5a‐ and NAP‐1/IL‐8‐specific dysfunction of pustule PMN as compared with blood PMN. In contrast, FMLP‐elicited functional activities of pustule PMN were only slightly affected.Our findings provide evidence that in inflamed tissue invading PMN are regulated by in situ generated mediators. C5a produced by staph. aureus‐induced activation of the alternative pathway of the complement cascade represents predominant regulatory factor in situ. Furthermore, the results substantiate previous observations concerning different modulation of C5a and f‐met‐peptide recep