Cutaneous manifestations of NAXD deficiency – A case report

Metabolism is a tightly regulated sequence of events, supported by key reactions between enzymes and enzyme-specific substrates. These reactions have the potential to produce metabolic side products that can have deleterious effects to further key metabolic reactions. The nicotinamide repair system consists of two partner enzymes, NAD(P)HX epimerase (NAXE) and NAD(P)HX dehydratase (NAXD). These enzymes regulate the levels of metabolic side products. Here we present a case of an 11-month old child who presented to our paediatric department with pyrexia, lethargy and multiple cutaneous lesions on the background of NAXD deficiency, a lethal neurometabolic disorder of early childhood. Despite early intervention with intravenous antibiotics, the patient failed to improve and subsequently passed away. The skin lesions were thought to be a consequence of systemic disease rather than a propagator of infection. Clinicians should be aware of this incredibly rare metabolic disease, its potential to cause widespread systemic dysfunction and the developing avenues for management.