Widespread Erythematous Scaly Eruption in an Infant with Phenylketonuria

An 11-month-old girl with phenylketonuria (PKU) presented with widespread erythema, desquamation, sparse hair, and other symptoms due to severe phenylalanine (Phe) deficiency from a strict Phe-restricted diet. Initially misdiagnosed as eczema, her condition was identified as an acrodermatitis enteropathica-like eruption secondary to Phe deficiency. Despite zinc supplementation, her skin lesions worsened, prompting hospitalization and treatment with intravenous human albumin and regular formula feeding to restore Phe levels. This led to rapid improvement in her symptoms, including skin lesions and hair regrowth. The case underscores the importance of monitoring blood amino acid levels and recognizing metabolic dermatitis in patients with eczematous eruptions unresponsive to standard treatments.