Neonatal acne, also known as acne neonatorum, is an acneiform eruption that occurs in newborns or infants within the first 4-6 weeks of life, and presents with open and closed comedones on the cheeks, chin and forehead.The main cause is not known for certain but it may be caused by maternal androgens transferred from the mother to the newborn from the placenta and androgens produced by the fetal adrenal gland and neonatal testicles that stimulate sebaceous glands to increase production of sebum. As a self-limiting condition, neonatal acne tends to resolve on its own but treatment options can include topical benzoyl peroxide, topical retinoids, topical antibiotics and topical antifungals. Signs and Symptoms
Neonatal acne presents from birth to within the first 4-6 weeks of life. Common symptoms are open and closed comedones such as papules and pustules that occur most commonly on the face on the areas of the cheeks, chin and forehead. Less commonly, lesions can be present on the chest and back. Causes
It is believed that maternal androgens passed to the infant through the placenta has a role in stimulating sebaceous glands leading to increased sebum production that causes comedone formation.
A delayed hemolytic transfusion reaction (DHTR) is a type of transfusion reaction. According to the Centers for Disease Controls (CDC) National Healthcare Safety Networks (NHSN) Hemovigilance Module, it is defined as:

Mechanism
If a person without a Kidd blood antigen (for example a Jka-Jkb+ patient) receives a Kidd antigen (Jka-antigen for example) in a red blood cell transfusion and forms an alloantibody (anti-Jka); upon subsequent transfusion with Jka-antigen positive red blood cells, the patient may have a delayed hemolytic transfusion reaction as their anti-Jka antibody hemolyzes the transfused Jka-antigen positive red blood cells. Other common blood groups with this reaction are Duffy, Rhesus and Kell. Diagnosis
Positive direct antiglobulin test (DAT) for antibodies developed between 24 hours and 28 days after cessation of transfusion
Positive elution test with alloantibodies present on the transfused red blood cells OR newly identified red blood cell alloantibodies in recipient serum.Antibody elution is the process of removing antibodies from the surface of red blood cells. Techniques include using heat, ultrasound, acids or organic solvents. No single method is best in all situations. In an elution test, the eluted antibodies are subsequently tested against a panel of reagent red blood cells of known phenotype. Inadequate rise of post-transfusion hemoglobin level OR rapid fall in hemoglobin level back to pre-transfusion levels OR otherwise unexplained appearance of spherocytes.PROBABLE DIAGNOSIS

Newly identified red blood cell alloantibody demonstrated between 24 hours and 28 days after cessation of transfusion BUT incomplete laboratory evidence to meet definitive case definition criteria.