Definition of Myxedema, infantile

Myxedema, infantile: Hypothyroidism (subnormal activity of the thyroid gland) that starts after birth and is manifest by features including delays in growth and development and myxedema surfacing during infancy. Myxedema is a dry waxy type of swelling, often with swollen lips and nose. Infantile myxedema is also called infantile hypothyroidism. Another name, now little used, for the condition is Brissaud's infantilism, after the French physician Edouard Brissaud (1852-1909).