Pellagra and Scurvy in a Patient With Relapsed Schizophrenia

A 64-year-old male was admitted to hospital for relapsed schizophrenia. He was referred to the dermatology unit for widespread scaly plaques. Minimal history was obtained from the patient due to poor engagement with the treating clinicians. A collateral history revealed 8 weeks of mental health decline, characterised by paranoia, social withdrawal, poor oral intake and self-neglect. The skin lesions had been present for weeks, but the patient had not sought any treatment for this. Diarrhoea of unknown duration was also noted. His history was significant for schizophrenia, diagnosed 8 years ago. He had experienced multiple relapses, with an admission 3 months prior to this presentation. At that time, he was discharged back to the community team but was lost to follow-up. Examination revealed a photodistributed dermatitis with a well-demarcated erythematous, hyperpigmented scaly plaque in a V-shape on the anterior neck and chest. Similar scaly hyperpigmented plaques on the forearms and legs were noted (Figure 1). On the trunk, there were scattered purpuric perifollicular papules and nodules. There was no evidence of ecchymosis, nor were there corkscrew hairs. Poor dentition was noted without oral mucosal lesions. Examination of hair and nails was otherwise unremarkable. A nutritional panel revealed undetectable vitamin C levels (< 3 μmol/L) and low vitamin D (15 nmol/L) and low zinc levels (5.8 μmol/L). Due to the patient's mental state, a 24-h urine collection was unable to be obtained to measure vitamin B3 levels. Blood tests on admission also demonstrated anaemia (haemoglobin 86 g/L), leukopaenia (white cell count 2.6 × 109/L), hyponatraemia (133 mmol/L) and severe hypokalaemia (2.3 mmol/L) and hypophosphataemia (0.20 mmol/L) (Table 1). A clinical diagnosis of pellagra was made due to the presence of the typical Casal necklace, photodistributed dermatitis and unexplained diarrhoea. The patient was also diagnosed with scurvy, given the undetectable vitamin C levels and findings of purpuric perifollicular papules and poor dentition. The anaemia, leukopaenia and electrolyte derangements were thought to be secondary to severe malnutrition. The patient was treated with nicotinamide 500 mg twice daily and vitamin C 500 mg daily. He also received aggressive electrolyte replacement and monitoring. Intravenous thiamine 300 mg twice daily for 3 days was administered and then switched to oral thiamine 300 mg daily. Under the guidance of a dietician, he was commenced on a high-energy diet with additional oral nutritional supplements and his refeeding syndrome was carefully managed. After 4 weeks, there was near complete resolution of the skin lesions (Figure 2). The diarrhoea also resolved shortly after commencing nicotinamide. The patient's haemoglobin levels improved without transfusion (100 g/L) and his leukopaenia and electrolyte derangements resolved. While traditionally associated with food scarcity and poverty, in developed countries, pellagra is confined to populations with certain risk factors, including chronic alcohol abuse, diet restriction, malabsorptive states secondary to gastrointestinal disease, and isoniazid therapy [1]. Neuropsychiatric symptoms of pellagra include fatigue, depression, apathy, confusion, hallucinations and delusions [2]. In some instances, pellagra may even present as new-onset psychosis [3]. In our patient, the negative symptoms of relapsed schizophrenia led to profound nutritional deficiencies through self-neglect, which likely exacerbated his neuropsychiatric symptoms. Scurvy is characterised by defective collagen synthesis secondary to severe vitamin C deficiency, resulting in gingival swelling, ecchymosis and poor wound healing [4]. As in our case, anaemia and leukopaenia may also be present [4]. One study showed that vitamin C levels decline rapidly to undetectable levels when dietary vitamin C is omitted [5]. This emphasises the need to consider scurvy in vulnerable patients. Our case is unique in that the aetiology of pellagra and scurvy was severe negative symptoms of relapsed schizophrenia. Although it has previously been reported that the average diet of individuals with schizophrenia contains sufficient vitamins and minerals, self-neglect can significantly alter this balance [6]. If suspected, initiation of oral nicotinamide and vitamin C is a safe, low-cost and effective treatment, which results in rapid improvement of signs and symptoms. Clinicians should therefore be aware of these conditions and their associated risk factors to avoid missed or delayed diagnosis. No AI was used at any stage of this manuscript preparation. Written informed consent has been obtained from the patient's next of kin, as the patient did not have the capacity to consent to publication. The authors declare no conflicts of interest. The data that support the findings of this study are available from the corresponding author upon reasonable request.