70-year-old man admitted for deterioration in general condition, asthenia, anorexia and weight loss of 1 month's duration. He had undergone surgery for adenocarcinoma of the prostate and had subsequently received several sessions of radiotherapy (total dose 70 Gy), the last of which was 12 months before his admission, in treatment with hormone therapy. Since starting radiotherapy treatment, the patient reports a change in intestinal rhythm, with alternating diarrhoea and constipation and frequent colicky pain, accompanied by urgency and tenesmus of defecation. Physical examination revealed only a soft, depressible, non-painful abdomen, with increased, non-pathological sounds, without obstructive signs, masses or megaliths. There were no adenopathies, fever or other noteworthy findings. Laboratory tests showed leukocytosis of 21,720 /mm3 (17.2% neutrophils, 4.1% lymphocytes, 2.4% monocytes and 75.3% eosinophils), ESR 60 mm in the first hour, CRP 38.80 mg/L, ferritin 481 ng/mL, rheumatoid factor 800 as acute phase reactants, hypoalbuminaemia of 2.2 g/dL without alteration of other markers of malabsorption. Transaminases and cholestasis enzymes were normal. Anti-nuclear, anti-mitochondrial and anti-smooth muscle antibodies were negative and PSA was 0 ng/mL. Stool parasitology in 3 conveniently collected samples was also negative. Chest X-ray showed no significant alterations. Colonoscopy was performed and the mucosa of the 30 cm explored showed a tubular fibrotic appearance with erythematous stippling, with regular fibrotic stenosis at this level that prevented progression. Multiple biopsies were taken showing acute and chronic non-specific inflammation, with no evidence of eosinophils at any level, and the presumptive diagnosis was actinic colitis.
Abdominopelvic CT scan with intravenous contrast showed diffuse thickening of small bowel loops at the level of the distal jejunum and ileum, with no other alterations. There was no evidence of lymphadenopathy at any level or abdominal masses, with radical prostatectomy and thickening of the perirectal fat, bladder wall and rectum, probably related to previous radiotherapy.
Due to the alterations in the loops, an intestinal transit was performed which showed a discrete thickening of the connivent valves at the level of the jejunum, with loops of pelvic ileum of reduced calibre, with separation from both the jejunum and the rest of the ileum due to parietal thickening, all compatible as a first possibility with actinic enteritis, and the last ileal loop being of normal calibre with preserved folds.
Given that the scans performed pointed to radiotherapy as the origin of the abdominal symptoms, and other causes of secondary peripheral eosinophilia having been reasonably ruled out, empirical treatment was prescribed with corticosteroids (methylprednisolone 1 mg/kg/day for 1 week, with a subsequent tapering regimen for 3 months) and parenteral nutrition, given the progressive deterioration of the patient's general condition. This treatment completely resolved both the clinical picture and the analytical alterations, which ruled out the central origin of the eosinophilia.
One week after starting treatment, the patient was discharged with a CBC showing 5,280 leukocytes/mm3 with 1% eosinophils, ESR 27 mm in the first hour and CRP 0.76 mg/L, with the diagnosis by exclusion of actinic enteritis and secondary peripheral eosinophilia. He remained asymptomatic and with normal laboratory tests.
