RESUMO
Eosinophilic colitis is a rare entity of unknown etiology characterized by diarrhea, abdominal pain, and gastrointestinal bleeding. Diagnosis includes histopathological infiltration of more than 20 eosinophils in colon. It is frequently associated with milk hypersensitivity and, less usual, with other foods and increased IgE. Histopthological appearance of eosinophil mediators has been observed in the gut. It is sometimes related to the degree of infiltration of eosinophils in the gut as well as to the disease severity. There is not an established treatment for this entity, although systemic steroids have been used with certain efficacy. However, there is a recurrence of the symptoms when the therapy stops, besides the well known side effects of the long-term use of steroids. Cromolyn inhibits mast cell degranulation and prevents liberation of mediators. It is successful in certain cases, specially the severe ones. However, it is not available for its use in our country. Ketotifen, as last resource in our patients with bad response to habitual treatment and restriction diet, was used. Although its use is controversial, we consider that stabilizing mast cell membrane with subsequent inhibition of degranulation and recruitment of eosinophils to sites of inflammation, would also restrain histamine liberation and blockage of H1 receptors, which would diminish local damage induced by eosinophils. Nonetheless ketotifen mechanism of action is unknown, our patients improved after treatment with this drug.
