Ulcerative colitis and isotretinoin: Is there a causal relationship?

We are reporting the case of a 39-year-old woman without toxic habits and with a history of mild mitral valve prolapsed that, after treatment of acne with dermatologist prescribed isotretinoin, consulted because of an increase in the number of bowel movements and bright red blood rectal bleeding after defecating without accompanying anal symptoms. The analytical study was normal and a colonoscopy was performed. Signs of inflammation were found in the distal 10 cm of rectal mucosal and had an erythematous and granular appearance with effacement of the submucosal vascular pattern and non-confluent micro-ulcers. All of this is suggestive of ulcerative proctitis (Fig. 1). The histological study showed an alteration in the glandular architecture with a reduction of goblet cells without observing crypt abscesses and with dense inflammatory infiltrate of plasma cells in the lamina propria. The patient was treated with topical mesalazine via suppository, initially at a dosage of 1 g/12 h and dosage was subsequently continued at 1 g/24 h. There was a clinical response; cessation of rectal bleeding and intestinal rhythm normalisation was observed. In the three years that the patient has continued follow up at our office, she has shown isolated outbreaks that have been controlled with topical mesalazine treatment, as needed. Discussion