Acrodermatitis Dysmetabolica: A Masquerade

Abstract Maple syrup urine disease (MSUD) is a rare autosomal-recessive inborn error of branched-chain amino acid (BCAA) metabolism. It is caused by enzymatic defect in the metabolic pathway of branched chain amino acids (leucine, isoleucine, valine) which leads to accumulation of BCAAs and corresponding keto acids in plasma, urine, and cerebrospinal fluid. The incidence of MSUD is approximately 1 in 185,000 worldwide. We present an infant with MSUD developed cutaneous lesions while on dietary treatment. 4 months old male baby was brought to hospital with complaints of excessive cry, poor feeding, failure to thrive. Initial biochemical investigations showed metabolic acidosis, normoglycemia, and ammonia was 65 μmol/L, and lactate was 2.7mmol/. Serum electrolytes, renal function tests were normal. CSF analysis was normal. Cutaneous examination revealed well defined erythematous patches over perianal area extending onto intergluteal cleft posteriorly, groins, and scrotum anteriorly. Multiple discrete erythematous macules and patches present over upper limbs, retro auricular areas, Hemorrhagic crusts were present at both upper lips and lower lips. These skin lesions developed few days after initiation of MUSD diet.