INTRODUCTION: Koebner phenomenon in psoriasis presents development of psoriatic 
lesions, after injury of uninvolved skin, which are identical in morphology with 
the previous trauma. The aim of this study was to establish the correlation of 
Koebner phenomenon with sex and age distribution, clinical variants of psoriasis 
vulgaris, age of onset and incidence in psoriasis among relatives of affected 
patients.
MATERIAL AND METHODS: Sixty patients, with severe clinical picture, participated 
in this study: 38 patients in acute flare of a chronic form; 10 with acute 
exanthematic form; 8 with a chronic stable form; 3 with psoriatic changes on 
palms and soles and one patient with psoriatic erythroderma. According to the 
presence of Koebner phenomenon they were divided in two groups, one with 
positive and the other with negative Koebner phenomenon which presented the 
control group at the same time.
RESULTS AND DISCUSSION: The Koebner reaction is often thought to be more 
frequent in actively spreading, severe psoriasis. Although this may be true, it 
has to be established by prospective studies. According to our investigation, 
Koebner phenomenon did not depend on clinical picture of psoriasis vulgaris. 
This reaction also appears to be a marker for a subgroup of patients with a 
tendency to early onset, but that was not confirmed by our study. In available 
literature we did not find any data about relations of Koebner phenomenon to sex 
and age or familiar incidence of psoriasis vulgaris. Our results demonstrated no 
connection of Koebner phenomenon with sex and age structure. At the same time 
its presence did not depend on familiar incidence of psoriasis vulgaris.
CONCLUSIONS: There is no relationship between Koebner phenomenon and sex and age 
distribution. It does not depend on clinical picture and also does not predict 
the age of onset and familiar incidence of psoriasis vulgaris.