The skin plays a very important role, acting as a barrier between the outside of the body and the inside. It is comprised of three layers, the epidermis, the dermis and the hypodermis. The epidermis is the most superficial; forming a literal barrier from the elements, the cells within this layer are constantly renewed. Underneath this layer lies the dermis, which is responsible for providing much of the skin’s mechanical strength. The third and deepest layer is the hypodermis; with pockets of adipose tissue, this layer provides insulation and protection to the underlying organs.
The skin composition is not consistent across the body; it is thicker in areas such as the soles of the feet and palms of the hands, which get more mechanical use. It also varies in laxity, mechanical strength, pH and moisture.
Dry skin, known medically as xerosis, is very common. It affects males and females of all ages. One of the main symptoms is itching, this is often accompanied by flaky skin, cracking and patches of dryness, which causes the skin to feel tighter and rough. Dry skin is usually caused by a lack of moisture in the epidermal layer. As well as being protective, this layer contains lipid molecules and very specific proteins, including filaggrin, which prevent dehydration. Genetic conditions can affect the function of these proteins, resulting in a loss of water retention in the epidermis, and causing the skin to become dry and sensitive.
The skin is a very valuable tool with regards to informing on a person’s health, and its structure has been shown to degenerate in response to aging, obesity and some diseases. This article aims to review some of the most common conditions that challenge the integrity of the skin by exploring how the skin is altered and what measures can be implemented to alleviate the symptoms.
Atopic dermatitis (eczema)
Atopic dermatitis is a chronic inflammatory disease, characterised by persistent itching. It is the most common type of eczema and usually starts during childhood. Most people outgrow the condition, although their skin remains sensitive and highly susceptible to irritation.
The exact pathogenesis of atopic dermatitis is unknown; however, it is thought to involve a complex interplay between dysfunction of the skin barrier (genetic or environmental), a faulty immune response and hypersensitivity of the subcutaneous layer of the skin. One gene known to be involved is filaggrin, which, under normal conditions, maintains hydration of the skin. The involvement of at least one mutated gene explains why atopic dermatitis appears to run in families. The heightened sensitivity of the skin is likely to be caused by an increase in the density of epidermal nerve fibres lying under the surface of the skin.
Most patients with atopic dermatitis will find that there are certain triggers that exacerbate their condition; these can include soaps, detergents, cosmetics, wool, dust and sand. Furthermore, stress, whilst not considered to be causative, certainly seems to worsen the symptoms.
Some of the most frequently observed symptoms are redness, swelling, blisters, cracked skin and weeping sores. Dry skin is very common and any inflammatory response is made worse by scratching. Persistent itching can be very detrimental to a person’s quality of life, thus finding a way of alleviating the sensation is very important. One option is to use an emollient-rich moisturiser, applied to damp skin, which inhibits the evaporation of water. This is actually best done as a preventive treatment, so prior to, or in anticipation of, a flare up. Using a moisturiser that is designed for use on sensitive skin will hopefully avoid further problems.
Psoriasis is a chronic autoimmune condition, believed to affect up to 2% of the population. In its most common form, psoriasis vulgaris, plaques of thickened scaly skin are visible on the elbows, knees and scalp. The silvery-white flakes that are usually seen are due to rapid proliferation of the underlying dry skin cells. It is usually diagnosed in early adulthood, however can affect both men and women of any age.
The exact cause of psoriasis is not known. It is thought to be due to a complex interplay between genetic and environmental factors, which leads to an over-active inflammatory response in the skin. Psoriasis often co-presents with joint pain and arthritis, meaning management of the condition frequently involves a multi-disciplinary team, that includes dermatologists and rheumatologists. The condition also has a strong association with other inflammatory conditions, such as diabetes and cardiovascular disease, highlighting a need for regular monitoring.
Whilst not curable, the symptoms of psoriasis can be managed and patients often go into remission. One major factor is the impact that the condition can have on a patient’s quality of life, with many finding that the appearance of their skin negatively affects their self confidence.
Mild cases of psoriasis may respond well to treatment with topical lotions, including mild steroid creams and moisturisers. For those with a more severe form, UV therapy, steroid injections and medications are all viable treatment options. If the scalp is affected, special psoriasis shampoos can be effective. Recent developments in terms of psoriasis treatment are biologic therapies, which are usually given in the form of antibodies, which target the parts of the immune system that are over-activated in psoriasis patients.
Approximately 12% of people will experience a problem with their thyroid gland during their lifetime and women are eight times more likely to be affected than men. Hypothyroidism results from an underactive thyroid gland, meaning that insufficient levels of thyroid hormone are produced. It can be a difficult condition to diagnose as symptoms are often non-specific and easily attributable to other disorders. Some of the most frequently observed symptoms are tiredness, weight gain, generalised weakness, heavy or irregular periods and itchy dry skin.
In one study, more than 70% of hypothyroid patients reported dry skin, suggesting it is one of the most common symptoms. Low levels of thyroid hormone result in a slow down of metabolism, which causes reduced sweating (sweat is the body’s natural moisturiser), and means that the body’s cells have less capability to repair and replace themselves. This has a major impact on cells with a rapid turnover rate, including hair and skin cells. The skin becomes rough and the epidermal layer thins. Skin on the soles of the feet and palms of the hands becomes particularly dry.
Prompt identification of changes to the skin can be lifesaving; myxedema is a serious complication of untreated hypothyroidism. One of the first signs is a red, swollen rash. Immediate medical aid should be sought in cases of suspected myxedema.
Fortunately hypothyroidism is treatable, usually with synthetic hormone tablets. Restoring levels of thyroid hormone should alleviate most of the symptoms, including problems with the skin. In the meantime, dry skin can be soothed using a humectant-rich moisturiser.
Diabetes is a chronic condition characterised by high blood sugar levels. Insulin is a hormone produced by the pancreas which regulates blood sugar levels, preventing them from getting too high. Diabetes is caused by either insufficient insulin production (type 1 diabetes) or the inability of the body to use insulin properly, resulting in insulin resistance (type 2 diabetes). Some women experience gestational diabetes during pregnancy because the hormones produced by the placenta induce insulin resistance. This type of diabetes is controlled by diet and usually disappears post-childbirth, although women who have experienced it are at higher risk of developing type 2 diabetes later in life.
Patients with type 2 diabetes may be able to control their condition with their diet. However, those with type 1 diabetes will require lifelong insulin treatment.
Some of the most common symptoms of diabetes are increased thirst, frequent urination, unexplained weight loss despite an increased appetite, fatigue, blurred vision and regular infections. The skin is particularly affected in diabetes, and there are a number of skin conditions associated with diabetes, collectively named diabetes dermadromes. Between 40-70% of diabetic patients experience some form of skin pathology. The skin becomes particularly prone to both bacterial and fungal infections, as well as patches of localised itching and dry skin (xerosis). It is still not fully understood why diabetes has such a profound effect on the skin, however, one proposed theory for why so many patients experience dry skin is that the body is using all the water it can to get rid of the excess blood sugar. Other factors thought to be involved include an altered immune response, nerve damage and changes to the structure of the collagen located within the epidermis.
A good moisturiser will prevent further moisture loss and provide soothing relief to skin that is uncomfortable and inflamed. Infections cause the skin to become hot, swollen, red and easily aggravated. Whilst these infections are highly prevalent in patients with diabetes, following a good skin care routine can reduce the risk. Mild soaps and moisturisers are recommended to ease the burden of regular infections.
Some skin conditions are particularly prevalent in those patients with diabetes, these include diabetes dermopathy and necrobiosis lipoidica diabeticorum, which both cause brown scaly patches; acanthosis nigricans, which is a form of hyperpigmentation; and diabetic blisters, which resemble burns, although are usually painless. Treatment options for necrobiosis lipoidica include UV light therapy, low-dose aspirin and corticosteroids. For acanthosis nigricans and diabetic blisters the best treatment option is typically to control blood sugar levels through diet or synthetic insulin.
Hormonal changes (pregnancy and the menopause)
Striae gravidarum (stretch marks) and hyperpigmentation occur in up to 90% of pregnancies. Both are thought to be due, in part, to hormonal changes, specifically increased levels of oestrogen and relaxin. Stretch marks are pink and purple lines that form across the expanding abdomen, breasts, buttocks and thighs. Much maligned by the majority of women who are affected, the beauty industry readily markets most pregnancy-related products as ‘stretch mark treatment’, however, scientifically there is little evidence that they actually work. Hyperpigmentation usually affects the areolae or genitalia. A particularly common manifestation of the condition is the linea nigra, which appears down the centre of the abdomen. Some pregnant women experience a form of hyperpigmentation on the face, known as melasma, or the ‘mask of pregnancy’. As with stretch marks, there is no medically approved cure, although most skin tone changes will resolve following delivery. It is recommended to avoid excess sun exposure as this can exacerbate the condition.
During pregnancy, existing skin conditions may worsen or improve. One study found that for pregnant women with atopic dermatitis, approximately half saw a worsening of symptoms and a quarter saw an improvement. The symptoms of psoriasis usually improve during pregnancy. The reason for these changes in some women, but not others, remains unclear, however, a hormonal link is likely.
Pregnant women are also at increased risk of developing rashes, usually accompanied by dry, itchy, uncomfortable skin. Examples include pruritic urticarial papules and plaques of pregnancy (PUPP), which is a form of dermatitis, and intrahepatic cholestasis, which can cause intense itching. The former is relatively harmless, treated with antihistamines and usually resolves following delivery. The latter can be very serious, causing premature delivery or foetal distress and, thus, requires careful monitoring.
Itchy, dry skin during pregnancy can be treated with gentle moisturisers.
Pruritus, or itchy skin, starts during the perimenopause, which is the period of time that precedes the menopause. Generally considered to occur in response to reduced levels of oestrogen, the skin produces less collagen and fewer natural oils. The net result of this is thin, dry, itchy skin that has less elasticity. Some menopausal women also experience a flare up of existing skin conditions, such as psoriasis, usually attributed to a change in hormone levels. Evidence for this comes from the correlation between higher oestrogen levels during pregnancy and improved psoriasis symptoms, compared with lower oestrogen levels during the menopause and a worsening of symptoms. Many women choose to alleviate their menopausal symptoms with hormone replacement therapy (HRT). Restoring oestrogen levels counteracts many of the negative effects attributed to the menopause, including improving skin tone and texture.
Humectant-rich moisturisers can also provide soothing relief to uncomfortable skin and it is proven that certain nutrients, such as vitamin C, can enhance the body’s production of collagen.
Pregnancy and the menopause can both trigger acne. This is best treated with gentle cleansers and a good skin care routine.
With increasing age comes mechanically fragile skin that can be very dry and lacking in elasticity. Cellular processes slow down naturally with age, which impairs certain physiological functions, such as wound healing; this makes blemishes and scars more visible. Wrinkles form because skin laxity is lost due to reduced collagen production. Most of these changes are thought to also be due to reduced hormone levels. Adopting a good skin care routine, can lessen the physical signs of aging, as can taking steps to implement a healthy lifestyle. Avoiding excess alcohol and smoking, eating a balanced diet, exercising more, applying sunscreen regularly and getting plenty of sleep are lifestyle changes that everyone could benefit from. In combination, adopting these good practices will help to improve your overall health, in addition to enhancing the appearance of your skin.
Chemotherapy can have quite a drastic effect on the skin. A number of the most common chemotherapeutic agents in use today can cause fragile and extremely dry skin. The constantly regenerating skin cells are vulnerable to attack by cancer drugs which are designed to target rapidly reproducing cells. The skin barrier is compromised, lessening its protective abilities against environmental insults, resulting in immune activation and leading to a heightened reaction to irritants.
One way of combating the negative effects that chemotherapy may have on the skin is to use emollient-rich moisturisers. The Cancer pack is designed to help those women who are undergoing treatment for cancer. With a specially-designed formulation, rich in humectants, it provides moisture to painful, dry skin, and brings soothing relief to areas of inflammation.
For a comprehensive review on the effects of chemotherapy on skin, click here.
Medication used to treat high blood pressure (antihypertensive drugs) can cause a range of side effects, including headaches, tiredness and skin rashes. Other frequently prescribed drugs that can adversely affect the skin include diuretics, beta blockers, ACE inhibitors and angiotensin II receptor blockers. Due to the possibility of adverse drug reactions (ADRs), lifestyle changes are recommended as the first line treatment approach.
The most common dermatological side effects are rashes and eczema. In fact, eczema is responsible for half of the reported skin ADRs caused by hypertensive drugs. Pre-existing conditions, such as psoriasis, may also be aggravated. Management will depend on the severity of the symptoms. If the side effects become intolerable an alternative medication may need to be prescribed. For milder effects, moisturisers may provide adequate relief.
Antidepressants can also cause adverse skin reactions. The newer selective serotonin reuptake inhibitors (SSRIs) are generally better tolerated than the older tricyclic antidepressants (TCA), however, dry skin, acne and increased sensitivity to the sun are all common side effects. One skin complaint seen with SSRIs is erythema multiforme, which causes a rash that resembles ‘bull’s eye’ patches to appear. Normally fairly mild in nature, rashes should be monitored regardless, because they can be an early warning sign that a patient is developing hypersensitivity to a particular drug. If this is the case, an alternative treatment may be required.
For the majority of medications it is impossible to predict how well a patient will tolerate both the drug itself and the side effects. Skin rashes and their related pathologies are a common side effect to many medications in use, although fortunately they are usually relatively mild and manageable. Provided quality of life is not impacted and the skin reactions remain mild, the optimum approach for controlling them is to adopt a good skincare routine, using gentle moisturisers, rich in antioxidants. Choosing a product with natural SPF protection is also recommended.
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