The medical term “anhidrosis” means an inability to sweat. It is sometimes referred to as hypohidrosis. Though this may sound pretty harmless, it is, in fact, a serious condition and in some severe cases can be life-threatening. So, what is congenital anhidrosis?
This is because the body needs perspiration in order to maintain a healthy temperature.
Your metabolism and muscles create heat as they work. Your core temperature increases as you exercise or become exposed to an external heat source. As a natural process, as your temperature rises, your nervous system automatically sends messages to your eccrine sweat glands. The glands then produce fluid which is transferred on to your skin surface. As this sweat evaporates it acts as a natural coolant.
A healthy body would have around 2.6 million sweat glands. And just one drop of sweat can cool around one quart of blood by 1ºF.
Anhidrosis can be an absence of sweat on just one part of the body, or the entire surface. People with mild causes may actually not even realize that they have it. This means it is hard to know just how many people have this medical condition.
It can be caused by many different things. This can include a temporary phase due to injury or illness. This includes problems that cause pores to become blocked, stopping sweat from being deposited on the skin’s surface. Anhidrosis can also be a side-effect of using certain medications.
Impaired ability to sweat can also result from nerve damage caused by other medical conditions such as B-vitamin deficiency, gout, diabetes, and alcoholism. It can also arise from skin damage due to severe burns from fire, as well as exposure to chemicals and electricity.
When it only affects small areas of the body, it is possible to simply leave the functioning perspiration process to compensate for the deficient patch. In moderate to severe cases, it is important to try to identify and address the cause. When this level of anhidrosis is diagnosed, avoid strenuous exercise in warm environments.
One of the root causes of anhidrosis is a genetic flaw or an inherited disease. When you are born with this condition it is described as “congenital anhidrosis” and it is often associated with an inability to feel pain too.
The defect at birth that can result in an inability to perspire – and therefore cool your body naturally – is sometimes due to being born with no sweat glands or impaired sweat glands.
This can be particularly serious in the early years of life. If an infant can’t cool itself naturally, they may be prone to high temperatures, which can make them very ill. This may lead to seizures, and brain damage.
This congenital inability to sweat can occur, for example, in babies with hypohidrotic ectodermal dysplasia. Around 1 in 17,000 people worldwide are born with this condition.
Hypohidrotic ectodermal dysplasia is part of a group of similar genetic defects in humans. They result in fetuses developing abnormalities in structures such as their sweat glands, skin, teeth, hair and nails. In most cases of ectodermal dysplasia, the child has an impairment to the process of sweating, as well as sparse hair, chronic skin problems, and distinctive facial features.
This form of congenital anhidrosis is also referred to as hereditary sensory and autonomic neuropathy type IV.
Usually diagnosed soon after birth, it puts the child at great risk, not just from overheating but also from serious injury due to the fact the abnormality includes their pain sensors. If they don’t feel pain, they have no instinct to move away from situations that can damage them. However, this condition in itself is not fatal and can be managed.
This form of congenital anhidrosis is also characterized by thick, leathery skin, particularly on the palms of their hands, and distorted fingernails or toenails. Individuals with this condition may also have areas on their scalp with no hair growth as well as weak muscle tone and growth.
Around 50% of people with this condition also have some level of hyperactivity or emotional instability, and a substantial number have an intellectual disability.
Anhidrosis can also present in children born with the inherited condition called Fabry’s disease. This involves a build-up of a particular type of fat (globotriaosylceramide) in the body's cells. This leads to symptoms including pain (especially in hands and feet), skin areas showing small, dark red, cloudy corneas, hearing difficulties, as well as an impaired ability to sweat.
Fabry’s disease can be fatal, as it can lead to progressive kidney damage, heart attack, and stroke. These complications sometimes only appear later in life.