Coarse skin rash over an infant's torso due to hypothyroidism, the subnormal activity of the thyroid gland. If present at birth & left untreated, the condition may lead to cretinism, a syndrome of dwarfism, mental retardation & skin changes. The coarsening of the skin seen in this infant is termed myxoedema. Hypothyroidism is treated with supplementary doses of the thyroid hormone thyroxine.