Category: Functional Bowel Disease
New York City Department of Health and Mental Hygiene
Niacin Deficiency is an uncommon finding in developed countries and is usually secondary to poor dietary intake. A rare cause is Hartnup Disease, which leads to malabsorption of amino acids, specifically tryptophan. Patients may present with Pellagra, a constellation of symptoms that include dermatitis, diarrhea, and neurological abnormalities. We present a case of a patient infected with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) who presented with Pellagra and Niacin deficiency secondary to undiagnosed Hartnup disease.
A 46-year-old male without significant medical history presented with complaints of fever, polydipsia, polyuria, non-bloody diarrhea and dyspnea. Labs revealed a positive SARS-CoV-2 test. During his hospital course, the patient developed confusion, disorientation and required supplemental oxygen. His polydipsia and polyuria worsened and his diarrhea was persistent. His physical exam revealed a pigmented rash that was diffuse on bilateral lower and upper extremities. Niacin deficiency was suspected to be the etiology of his symptoms. A urine chromatography was obtained (Figure 1), which was consistent with Hartnup disease. Niacin supplementation was administered with subsequent resolution of the patient’s symptoms. He was discharged home with instructions to continue to take multivitamins.
Our case describes a patient infected with SARS-CoV-2, which may have led to amino acid deficiencies inducing pellagra in a previously asymptomatic patient with Hartnup disease. It has previously been reported that Severe Acute Respiratory Syndrome Coronavirus 1 (SARS-CoV-1) downregulates ACE2 expression in the GI tract. This leads to impaired amino acid absorption, specifically tryptophan. We hypothesize that similar to its previous generation, the novel SAR-CoV-2 may also downregulate ACE2 expression in the GI tract leading to malabsorption and a deficiency of amino acids. We suggest that it was by this mechanism that the patient’s infection precipitated symptoms of niacin deficiency in the setting of underlying Hartnup disease. This case serves to raise awareness that SARS-CoV-2 may be altering reabsorption of nutrients in the GI tract and leading to the development of new nutritional deficiencies or exacerbating previously undiagnosed inborn errors of intestinal nutrient absorption.
Christopher Tanchez indicated no relevant financial relationships.
Pardeep Taunk indicated no relevant financial relationships.
Neera Sinha indicated no relevant financial relationships.
John Trillo indicated no relevant financial relationships.