During the first 6–12 months of age, there is increased sebum production stimulated by luteinizing hormone (LH) and testosterone of testicular origin that stops after this period until adrenarche. Girls do not experience this.Genetics and family history play a role in influencing sebaceous gland size and activity, pore size and inflammation that can increase risk of onset and presentation of infantile acne.It is suggested that the fetal adrenal gland along with testicular androgen could be the cause of infantile acne. During the neonatal period, there is increased sebum production through an enlarged zona reticularis (an androgen producing area) on the fetal adrenal gland that gradually decreases to very low levels at around 1 years of age, coinciding with when infantile acne tends to resolve. The fetal adrenal gland produces androgens such as dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) that stimulate sebaceous glands. Diagnosis
Diagnosis is based on presentation of comedones primarily on the face of an infant of 6–12 months of age. Severity can be mild, moderate or severe and can be determined from the presence and distribution of comedones and inflammatory lesions such as papules and nodules. A physical may be followed up next with particular attention paid to signs of an endocrine disorder including normal growth and weight, testicular growth, breast development, hirsutism or growth of pubic hair. Hormonal workup may not be necessary unless one of these abnormalities is present, then work up of testosterone, DHEA, DHEAS, LH and FSH or referral to a pediatric endocrinologist specialist may be recommended.
Hypoxemia is an abnormally low level of oxygen in the blood. More specifically, it is oxygen deficiency in arterial blood. Hypoxemia has many causes, and often causes hypoxia as the blood is not supplying enough oxygen to the tissues of the body. Definition
Hypoxemia refers to the low level of oxygen in blood, and the more general term hypoxia is an abnormally low oxygen content in any tissue or organ, or the body as a whole. Hypoxemia can cause hypoxia (hypoxemic hypoxia), but hypoxia can also occur via other mechanisms, such as anemia.Hypoxemia is usually defined in terms of reduced partial pressure of oxygen (mm Hg) in arterial blood, but also in terms of reduced content of oxygen (ml oxygen per dl blood) or percentage saturation of hemoglobin (the oxygen-binding protein within red blood cells) with oxygen, which is either found singly or in combination.While there is general agreement that an arterial blood gas measurement which shows that the partial pressure of oxygen is lower than normal constitutes hypoxemia, there is less agreement concerning whether the oxygen content of blood is relevant in determining hypoxemia. This definition would include oxygen carried by hemoglobin. The oxygen content of blood is thus sometimes viewed as a measure of tissue delivery rather than hypoxemia.Just as extreme hypoxia can be called anoxia, extreme hypoxemia can be called anoxemia. Signs and symptoms
In an acute context, hypoxemia can cause symptoms such as those in respiratory distress.