Statistical definition of nailfold capillary pattern in patients with psoriasis.

BACKGROUND

The microvasculature plays an important role in the pathogenesis of psoriatic skin lesions. Our purpose was to try to define a psoriatic pattern in the nailfold capillary, to clarify the relationship between nailfold capillary microscopic changes and nail involvement and to note the general clinical features of psoriasis.

METHODS

Image analysis of nailfold capillaries was performed in 62 patients with psoriasis. The capillary pattern was defined statistically comparing it with that of 51 healthy volunteers. We attempted to differentiate the psoriatic pattern from normal controls with "canonical discriminant analysis."

RESULTS

Forty-nine of 62 patients with psoriasis could be differentiated from normal controls by our definition of psoriatic pattern that was significantly correlated with periungual psoriatic plaque, nail pitting, onycholysis, and the extent of the involved area.

CONCLUSIONS

Our data suggest that nailfold capillary changes reflect microvascular changes of psoriasis and that the nailfold capillary pattern is a useful tool in evaluating nail involvement and the severity of psoriasis.