Acrodermatitis Dysmetabolica as a Cutaneous Manifestation of Isoleucine Deficiency in Maple Syrup Urine Disease: A Systematic Review of Reported Cases
Bahareh Abtahi‐naeini, Motahar Heidari‐Beni, Noushin Rostampour, Naeimeh Davoudi, Sarah SeyedyousefiABSTRACT
Background and Aim
Maple Syrup Urine Disease (MSUD) is a metabolic disorder affecting branched‐chain amino acid metabolism. While neurological symptoms are well‐characterized, cutaneous manifestations such as acrodermatitis dysmetabolica (AD) caused by isoleucine deficiency remain underrecognized. This systematic review aimed to summarize reported cases of AD or acrodermatitis enteropathica‐like eruptions in patients with MSUD.
Methods
A systematic search of PubMed, Scopus, and Web of Science was conducted through June 2026. Case reports and studies describing dermatologic findings in MSUD patients with confirmed isoleucine deficiency were included.
Results
19 studies reporting 20 patients were investigated. Most cases involved infants presenting with erythematous, scaly, or erosive lesions primarily in periorificial and acral regions. All patients exhibited low isoleucine levels with normal zinc status. Isoleucine supplementation resulted in clinical improvement in nearly all cases.
Conclusion
Acrodermatitis dysmetabolica is a treatable dermatologic complication of MSUD, typically arising from dietary isoleucine deficiency. Early diagnosis and monitoring of amino acid levels are critical for effective management.