[Anal and perianal lesions in Crohn's disease].

Crohn's disease is not a homogeneous clinical entity but may shows many clinical pictures during its period, prognosis and response to therapy. Anal and perianal localisations are frequently found; they can occur isolated, months or years in advance the disease, or can be concomitant with an ileal, colic or rectal involvement. There can be many kinds of lesions: simple, such as eczema or fissuration, complex, such as high rectal or rectovaginal fistulas. A rational classification of anal and perianal manifestations is suggested. Local medical therapy, is very effective in minor lesions, and has to be associated with systemic medical therapy particularly nowadays: the knowledge on phlogosis, biology and biotechnology revolution, have launched a new therapeutic era. Surgical therapy can be performed only in case of complex disease non responsive to medical therapy or when it is necessary to give a rest to anorectal tract. To perform a correct follow-up, considering unpredictability of lesions, a careful clinical evaluation and an intensive surveying plan associated with objective evaluation parameters are suggested.