These patients are under the risk of severe hyperammonemia during infections that can lead to comatose states.Liver transplant is gaining a role in the management of these patients, with small series showing improved quality of life. Epidemiology
Propionic acidemia is inherited in an autosomal recessive pattern and is found in about 1 in 35,000 live births in the United States. The condition appears to be more common in Saudi Arabia, with a frequency of about 1 in 3,000. The condition also appears to be common in Amish, Mennonite and other populations with higher frequency of consanguinuity. History
In 1957, a male child was born with poor mental development, repeated attacks of acidosis, and high levels of ketones and glycine in the blood. Upon dietary testing, Dr. Barton Childs discovered that his symptoms worsened when given the amino acids leucine, isoleucine, valine, methionine, and threonine. In 1961, the medical team at Johns Hopkins Hospital in Baltimore, Maryland published the case, calling the disorder ketotic hyperglycinemia. In 1969, using data from the original patients sister, scientists established that propionic acidemia was a recessive disorder, and that propionic acidemia and methylmalonic acidemia are caused by deficiencies in the same enzyme pathway. See also
Methylmalonic acidemia
Isovaleric acidemia
Maple syrup urine disease

References
External links
Propionic acidemia at NLM Genetics Home Reference
Propionic acidemia at NIHs Office of Rare Diseases
"Propionic acidemia". Orphanet.
Transient neonatal pustular melanosis (TNPM), also known as pustular melanosis, is a transient rash common in newborns. It is vesiculopustular and made up of 1–3 mm fluid-filled lesions that rupture, leaving behind a collarette of scale and a brown macule. [3] This rash occurs only in the newborn stage, usually appearing a few days after birth[2], but is sometimes already present at birth[3]. The rash usually fades over three to four weeks  but may linger for up to three months after birth. [3] It can occur anywhere on the body, including the palms and soles. [1][2][3]The cause of TNPM is unknown. No treatment is needed except for parental reassurance. Causes
The cause of TNPM is unknown but it is a common rash in newborns. [3]

Histopathology
Gram, Wright, or Giemsa staining of the pustular contents will show polymorphic neutrophils and occasional eosinophils. [2][3] On histopathology, the pigmented macules will show basal and supra-basal increase in pigmentation without any pigmentary incontinence. [3] Bacterial culture will be negative. [4]It has been suggested that TNPM is merely a precocious form of erythema toxicum neonatorum based on the similar histopathology. [4]

Diagnosis
Transient neonatal pustular melanosis is diagnosed clinically, based on appearance alone, with no need for special testing. Proper identification is important to distinguish it from other serious, infectious neonatal diseases[3] and to help avoid unnecessary diagnostic testing and treatments. Treatment
No treatment is needed except for parental reassurance. The rash spontaneously resolves, usually in three to four weeks,  but may linger for up to three months after birth.