Holocarboxylase synthetase deficiency presenting as ichthyosis.

Holocarboxylase synthetase deficiency is a rare autosomal recessive disorder of biotin metabolism. Clinical manifestations usually present within the first few days of life and include severe acidosis, feeding difficulties, breathing abnormalities, vomiting, seizures, progressive loss of consciousness, coma, and death. Skin findings, when present, usually develop within the first weeks of life and are described as an erythroderma-like dermatitis involving the eyebrows, eyelashes, and scalp. We were asked to consult on a newborn with a collodion membrane and severe metabolic acidosis who was eventually diagnosed with holocarboxylase synthetase deficiency and ichthyosis. The diagnosis of holocarboxylase synthetase deficiency might be considered in a newborn with collodion membrane, ichthyosis, and acidosis.