Vnitr Lek 2025, 71(8):E22-E27

Suspected pellagra in a patient treated with azathioprine for Crohn's disease

Pavel Polák¹, Michal Řiháček^{1, 2}, Andrea Wagnerová^{2, 3}, Alexandr Trunečka⁴, Petra Adamczyk⁴, Dalibor Váhala⁵

¹ Hematologicko-transfúzní oddělení, Nemocnice AGEL Prostějov

² AGEL Transfúzní služba, a.s.

³ Oddělení laboratorní medicíny, Nemocnice AGEL Prostějov

⁴ Interní oddělení, Nemocnice AGEL Prostějov

⁵ Laboratoře AGEL, a.s., Nový Jičín

Pellagra is a disease due to nutritional deficiency of niacin (vitamin B3). The main causes include nutritionally poor diet or impaired intestinal absorbtion. Other risk factors represent alcohol abuse, idiopathic bowel disease and immunosuppressive and antituberculotic treatment. Dermatitis, diarrhoea and dementia (3D) are characteristical clinical signs, untreated disease may lead to the death. The diagnosis is based on typical clinical signs which subside quickly after niacin supplementation. The authors present a clinical case of a patient with Crohn´s disease treated with azathioprine, who was acutely hospitalized for community-onset pneumonia, pancytopenia and symetrical sharply bordered maculous erythematous limb exanthema - clinically suspected of pellagra. The exanthema subsided completely within a week of parenteral niacin supplementation. Bone marrow examination led to the diagnosis of myelodysplastic neoplasia with low-blasts (MDS-LB). Niacin deficiency may have potentiated genotoxic effects of azathioprine. The patient was referred to the specialized hematooncological center.

Keywords: azathioprine, Crohn's disease, myelodysplastic syndrome, pellagra.

Accepted: November 26, 2025; Published: December 15, 2025  Show citation