What is Lanugo?
Lanugo is the name given to the fine non-pigmented hairs that grow on fetuses and are present immediately when a baby is born. In some cases, they are also seen as a result of certain medical conditions like anorexia nervosa. It is extremely common for a neonate or a newborn to have Lanugo. However, if it is present in older children or in adults then it almost always indicates an underlying pathological condition. It can be said that if a 25-year-old individual develops Lanugo then it is a cause for worry than a newborn baby having it. There are many mechanisms at the molecular level that play a role in the development of Lanugo. It plays a vital role in the normal development of the fetus. [1]
Lanugo is pivotal in holding the vernix caseosa together. The vernix caseosa is the white covering present when a baby is born which has various functions. It protects the skin of the baby, prevents any water loss from the body, helps the immune system, and regulates body temperature of the baby. It also protects the baby from any toxic substances that may be present in the amniotic fluid while inside the womb of the mother. Research suggests that Lanugo in combination with the vernix caseosa plays an major role in the fetus producing various hormones in the body for normal functioning. [1, 2]
The type of hair in an individual change over time as the child grows. Lanugo is the first type of hair that grows in a human being. Lanugo also controls the rate at which the fetus grows during the gestation period. Lanugo first grows in the fetus at the 12th week of pregnancy. It first grows around the eyebrows, nose and forehead areas and then spreads to cover the entire body. Lanugo generally disappears at about the 36th week of pregnancy. This is when the hairs merge into the amniotic fluid and mix to form the meconium. [1]
Lanugo is finally replaced by thin hairs called the villus and then terminal hairs which are the hairs that the baby then has during the time of birth. Often at times, not all Lanugo hairs are shed off and they remain in the body of the fetus when it is born. This is an extremely normal finding and is present in almost 30% of cases. It may remain for the first few weeks of life of the newborn before completely shedding off.[1]
However, presence of Lanugo becomes a cause of concern if an adult starts developing it. It is then a clear cut sign of an indwelling medical condition. The common medical conditions in which an individual can develop Lanugo are anorexia, malnutrition, bulimia, or some forms of cancer. This article highlights some of the potential causes of Lanugo in adults and ways to treat them.[1]
What Causes Lanugo?
Some studies suggest that presence of Lanugo occurs when the body tries to preserve heat. This is because Lanugo almost always develops in medical conditions where the body loses its ability to regulate temperature like anorexia nervosa. It is not always easy to observe growth of Lanugo in adults. However, this can be done by checking the areas of the body which did not have hairs before and now have growth of fine hairs like the face. Some of the causes for Lanugo developing in adults include:[2]
Eating Disorders: As stated, this is the most common cause of an individual developing Lanugo. Among all the anorexia nervosa is the primary condition which leads to the development of lanugo in adults. In fact, a study done in 2009 reveals that Lanugo is the primary symptom that indicates that an individual is suffering from anorexia nervosa.[2]
The study also revealed that people who develop starvation as a result of anorexia nervosa also tend to develop Lanugo. The growth of these fine hairs is seen more in the younger population and can be seen in the back, forearms, and the facial and neck region.[2]
Cancer: Some forms of cancer also have Lanugo as a symptom in adults. However, the occurrence of this is quite rare. A study done on this topic in 2007 revealed how an individual with prostate cancer developed lanugo type hairs and how they shed off once treatment commenced for this condition. It was an inconclusive study in that this observation was made only in one case and thus has been the only case where cancer has been connected to the growth of lanugo in adults. Thus more research needs to be done in a far higher scale to establish a clear link between Lanugo in adults and cancer.[2]
However, if one goes back in time and studies research done on this topic, there is mention of another case where an individual with lung cancer had Lanugo like growths on his hands, face, and feet. Again, the study was inconclusive and only one such incident was reported. These two cases have clearly intrigued researchers to look for more evidences on a supposed link between Lanugo and cancer.[2]
Celiac Disease: This is also believed to be one of the causes for Lanugo growth in adults. However, there is very little data available to conclusively establish a link between Lanugo and celiac disease as there was only one such incident when an individual with Lanugo growth had celiac disease. More research needs to be done in this respect to establish a clear link between these two conditions.[2]
How is Lanugo Treated?
Coming to treatment of Lanugo in adults, since it is not a medical condition but is rather the body’s response to certain other medical conditions there is no treatment required for it. In infants and newborns, Lanugo is quite common and sheds off within a few weeks after birth.[2]
Conditions like anorexia nervosa which are related to growth of Lanugo hairs in adults required treatment and once treated lanugo sheds off spontaneously. In cases where malnutrition is the cause of Lanugo then improved diet and treating the condition will clear away these fine hairs.[2]
In conclusion, lanugo is the name given to fine hairs that grow on the fetuses and helps in carrying out different functions. They act as a protector for the fetus by preventing them from toxic substances in the amniotic fluid. They also play a major role in the production of various hormones in the body. Lanugo develops during the first trimester and sheds off by the time the female reaches the third trimester of the pregnancy. However, in some cases these growths of hairs remain on the body at the time of birth. It is quite a normal occurrence and these hairs shed off within a few weeks of life of the newborn.[2]
However, if an adult develops Lanugo then it is a cause of concern as it indicates potential underlying medical conditions. Some studies have linked cancer and celiac disease to the growth of lanugo; however, these studies are inconclusive and cite only individual cases.[2]
Anorexia nervosa is believed to be the most common cause of Lanugo growth in adults. Lanugo does not require any treatment as it is not a medical condition. In people with eating disorders once the condition is treated these fine hairs shed off spontaneously.[2]
