Skin, important in regulating body temperature:

How climatic changes harm your skin

By Carol Aloysius

With weather patterns experiencing drastic changes today due to global warming, the skin is the most vulnerable part of the body to be affected by such extreme climatic changes.

Hot moist weather which we are now experiencing in contrast to the wet damp, cold weather can cause much damage to the skin apart from our health. Such damage, if not treated early, can leave unsightly scars that can remain for life.

Consultant Dermatologist, and Secretary, College of Dermatologists, Dr INDIRA KAHAWITA speaks to the Sunday Observer on common skin ailments that affect us, how they could be avoided and prevented and how they can be treated.

Excerpts ...

Weather patterns have changed drastically in our country during the past decade due to global warming. What are the effects of these changes on one's skin?

The skin plays a very important role in regulating the body temperature. Therefore a warm climatic condition will cause added stress on the skin. In addition, the increasing effect of UV radiation due to damage to the ozone layer also has some effects on the skin. This manifests as photo-dermatitis (sun induced skin rashes), photoageing and skin cancers, which we understand are long term effects.

Q. In the past three months we have experienced some very wet and cold weather. How does such weather impact on one's skin?

A. Cold weather can predispose to drying of skin which gives rise to eczemas and conditions like dandruff. Fungal infections become common during wet weather conditions. Condition like athlete’s foot, which occur due to excessive moisture are common during rainy weather.

Q. What can we do to protect our skin during a spell of cold and rainy weather?

A. Regular use of moisturisers, trying to keep away from moisture due to rain, drying of areas which are liable to retain moisture (e.g. toe web spaces) and treatment of minor skin problems may be of use.

Q. Most residents of up-country districts such as Nuwara Eliya are forced to wear heavy warm clothing to ward off the cold. Can wearing woolen jerseys, caps, stockings and socks and mittens all day and night lead to skin ailments? If so, what kind of skin disorders?

A. Some persons develop allergy to woollen material, which may present as itchy rashes in areas coming into contact with the woolen clothing. In some persons fungal infections may occur in skin flexures due to retained moisture.

Q. Can poor hygiene aggravate these disorders?

A. Yes, poor hygiene can aggravate infections. This can happen as frequent bathing and washing may not be possible during extremely cold spells.

Q. After the spell of rainy cold weather, we had in November and December; we are now experiencing some very hot weather which is causing us to sweat a great deal. What happens to the skin in such hot moist weather?

A. When there is hot and moist weather with increased sweating certain problems such as sweat rash and dandruff can get aggravated.

Fungal infections of the skin are also commoner during 'sweaty' weather. Eczema is another condition which flares up during this type of weather.

Another common problem is damage to skin due to excessive sun exposure. It is very common in school children who have been in the sun for the school sports-meet.

Q. How can these adverse effects be prevented?

A. The best type of prevention is keeping the skin as cool as possible. You should pay special attention to using cotton clothing, use of sun protection and regular washing/ bathing.

Use of fans or air conditioning may be use.

Q. What is the treatment you would recommend?

A. The treatment would depend on the condition.

Q. Where can it be obtained?

A. Most treatment including basic sun screens are available at the skin clinics in government hospitals.

Q. Sores (hori) and blisters are also common skin disorders at this time around. How are they caused?

A. Hori or scabies is due to a parasite (a microscopic mite) but blisters could be due to sweat rash or a bacterial infection.

Q. Who are the high risk groups?

A. Children are the most high risk group for scabies and bacterial blisters. Scabies can also occur in places where there is overcrowding like prisons or refugee camps.

Q. How can they be prevented?

A. Good hygiene is the most important factor in prevention. Regular bathing/ washing, using a mild shampoo or soap, use of clean clothing and bed linen are very useful in prevention. But the most important thing is to treat the infections effectively by following the instructions of your doctor correctly.

In case of scabies it is important to treat the entire household.

Q. What about boils and abscesses?

A. Boils and abscesses are due to bacterial infections. They are also common in children and people who have pre-existing medical problems like diabetes

Q. Many adolescents often complain that the hot climate causes them to break out with pimples. Apart from the hot weather, can this be due to changes in their sex hormones? Your comments?

A. Acne may become aggravated during hot weather in some persons. But the other causes are hormonal effects In some medications like steroids, mental and physical stress and cosmetics and skin care products can cause an outbreak of pimples.

Q. What is the danger of frequent touching, massaging, breaking and squeezing pimples? Will it leave permanent scarring?

A. Touching and breaking pimples may lead to secondary infection. But the most problematic thing is permanent scarring. If a young person develops deep scars due to acne these scars are likely to persist into adult life.

Q. Can they prevent or minimise the effects that hormonal changes cause on their skin?

A. Rather than the hormonal effects the other risk factors can be minimised or removed.

For instance, someone who has a tendency for acne should be very careful in using cosmetics and skin care products. It is very important to seek treatment for acne from a doctor at an early stage.

The treatment should be tailor-made for each individual. You may not benefit from the same treatment that worked wonderfully for your friend or sibling.

Talking about hormonal changes if there are any hormonal disorders they should be treated.

Q. Another common skin infection in this part of the world is Ring Worm infection. What is it? How is it caused? What are the symptoms? Is it infectious?

A. Ring worm is a fungal infection of the superficial layers of the skin.

The lesions are commoner in warm moist areas of the body like skin flexures (armpits and groins).

They appear as itchy scaly lesions which heal in the centre and spread outwards. It is infectious by touch (skin to skin) or through use if infected clothing etc.

Q. What is the treatment? Can it be done at home?

A. The treatment is with anti fungal creams or tablets. This can be done at home but the things to remember are the use of the treatment for at least four weeks and to avoid re-infection by disinfecting clothing and other material that come into contact with skin.

Q. Eczema is another common skin disorder in Sri Lanka. What is Eczema? How is it caused?

A. Eczema is an inflammatory condition of the skin.

This may occur as an allergic reaction to some material (contact eczema due to rubber slippers) or due to genetic factors. When eczema is due to genetic factors other conditions like asthma and hay fever may also be associated. Whatever the cause, dry skin is a predisposing factor for eczema.

Q. What is the treatment? Where is it available?

A. All skin clinics offer treatment for eczema. The treatment should mostly be aimed at correcting the dry skin with regular moisturisers.

Special soaps/lotions for dry skin may also help. Flare ups may be treated with steroids (either creams/ointments or tablets) depending on the severity.

Avoidance of aggravating factors, if identified, will also be helpful.

Q. Can babies get it? What is the treatment for infantile eczema?

A. Babies (from as early as three months) may develop eczema. The principles of treatment are the same as for adult eczema.

It is important to minimise sweating and avoid contact with irritants like soap, woolen material and urine.

Q. Whether it rains or sunny, schoolchildren are forced to wear closed shoes with socks during school hours. Can this lead to them developing skin ailments on their feet?

A. Wearing occlusive footwear can lead to increased sweating and worsening of eczema.

This may be minimised by use of cotton socks and use of canvas shoes rather than padded school shoes.

Q. What is athlete's foot? Is it caused by wearing closed shoes and having damp skin in between your toes?

A. Yes, athlete’s foot is a fungal infection due to collection of moisture between toes. It is commoner in people who wear shoes for prolonged periods of time. Another cause is excessive moisture in the toe web spaces.

Some people have less space between toes which is likely to cause collections of moisture. Such people should take extra care to dry the toe web spaces after a bath/ wash. Use of an anti fungal powder between toes before wearing socks and shoes may help in preventing this.

Q. As a Dermatologist, what kind of skin disorders do you see on the increase at present?

A. Eczemas are the commonest type of skin disorder seen in skin clinics.

In addition fungal infections such as ringworm and aluham, and bacterial infections like boils and abscesses and psoriasis are seen commonly.

At present there is an increase in the number of people presenting with problems related to the appearance like increased and decreased pigmentation.

But this could be due to a better awareness about cosmetic problems rather than an actual increase.

Q. Your message to children, adolescents and to the public in general?

A. Skin diseases are common conditions that need to be treated properly to achieve complete resolution. It is important to seek treatment early.

Inform the doctor about the treatment you have received previously, and if you can, show these medicines to the doctor.

Finally, follow the instructions carefully and continue the treatment as long as the doctor instructs.

Weight loss and gain linked to increased fracture risk

Both weight gain and weight loss in older (postmenopausal) women are associated with increased incidence of fracture, but at different anatomical sites, finds a study published in The BMJ.

The findings also challenge the traditional view that weight gain protects against fractures.

The influence of body weight on the risk of fracture is complex. Low body weight is a well recognised risk factor for fracture, but obesity also increases the risk of fracture at some sites. How fracture patterns differ after intentional and unintentional weight loss in postmenopausal women is also unknown.

So a team of US researchers investigated associations between postmenopausal change in body weight and incidence of fracture - and associations between voluntary and involuntary weight loss with risk of fracture.

They analysed data on over 120,000 healthy postmenopausal women who were taking part in the Women's Health Initiative Observational Study and Clincial Trials. Women were aged 50-79 at the start of the study (1993-98) and were followed for an average of 11 years.

Information such as age, ethnicity, body mass index (BMI), smoking, alcohol intake, physical activity levels, calcium and vitamin D intake was recorded at the start of the study.

Each year, participants were weighed and asked to report fractures of the upper limb (hand, wrist, elbow, upper arm, shoulder), lower limb (foot, knee, upper leg except hip, ankle), and central body (hip, pelvis and spine). Change in body weight was categorised as stable (a change of less than five percent from initial weight), weight loss (a decrease of five percent or more since initial examination), and weight gain (an increase of five percent or more since initial examination). Results at the third annual visit show that, during an average of 11 years of follow-up, compared with stable weight, weight loss was associated with a 65 percent increase in hip fracture, a nine percent increase in upper limb fracture, and a 30 percent increase in central body fracture. Also, compared with women who had stable weight, weight gain was associated with a 10% increase in upper limb fractures and an 18% increase in lower limb fractures, but no difference in central body fractures. Compared with stable weight, unintentional weight loss was associated with an increased risk of hip and spine fractures, whereas intentional weight loss was associated with an increased risk of lower limb fractures, but a decreased risk of hip fractures.

This study is the first to focus specifically on how weight change can differentially influence upper limb, lower limb, and central body fractures among postmenopausal women in the US, say the authors. The findings “have clinical and research implications and challenge the traditional clinical paradigm of weight gain protecting against fractures,” they add. “Clinicians should be aware that even intentional weight loss is associated with increased rates of lower limb fractures.”

An accompanying editorial discusses the implications for clinical practice. Juliet Compston, emeritus professor of bone medicine at Cambridge University, says unintentional weight loss of five percent or more in postmenopausal women “should be regarded as a risk factor for fracture, particularly hip fracture.”

The finding of an increased risk of fracture with intentional weight loss and with weight gain, albeit small, however, “emphasises the need for measures to prevent bone loss during interventions to reduce weight,” she said.

MNT

Researchers identify brain circuit regulating thirst

Scientists have identified a circuit in the brains of mice that regulates thirst. When a subset of cells in the circuit is switched on, mice immediately begin drinking water, even if they are fully hydrated. A second set of cells suppresses the urge to drink.

The thirst-regulating circuit is located in a region of the brain called the subfornical organ (SFO). “We view the SFO as a dedicated circuit that has two elements that likely interact with each other to maintain the perfect balance, so you drink when you have to and you don't drink when you don't need to,” says Charles Zuker, an HHMI investigator at Columbia University who led the research.

By doing so, the circuit ensures animals take in the right amount of fluid to maintain blood pressure, electrolyte balance, and cell volume.

Zuker's lab is primarily interested in the biology of taste.

Their studies have identified the receptors for the five basic tastes (sweet, sour, bitter, uammi and salt) and shown that the nervous system devotes multiple pathways to sensing and responding to salt.

These circuits ensure that salt is appealing to humans at low concentrations, but not at high concentrations.

“This is how the taste system regulates salt intake, which is very important for salt homoeostasis in the body,” says Oka.

“But this is just one side of the coin. Salt intake has to be balanced by water intake.” The scientists knew a different mechanism must be responsible for controlling an animal's water intake. “There are no concentration changes for water - water is water,” Oka says. “But when you're thirsty, water is really attractive.” Zuker and Oka set out to determine how the brain regulated the motivation to drink. They began their search in the brain region known as the SFO, which shows increased activity in dehydrated animals. The SFO is one of the few regions of the brain located outside the blood-brain barrier, meaning it has direct contact with body fluids.

“These cells might then have the opportunity to directly sense electrolyte balance in body fluids,” Zuker points out.

- MNT