Dermatitis (sometimes also called eczema simply means inflammation of the skin, and so contact dermatitis is the name used when this inflammation is caused by direct or indirect contact of the skin with something in your environment that it reacts to. What causes contact dermatitis? There are two main types of contact dermatitis: Irritant contact dermatitis. This type develops when the skin comes into contact with things that irritate the skin, such as detergents or very hot water that strip the skin of its natural oils and so dry it out. If you have regular contact with these you can then get an irritant dermatitis. This means it’s common in people who put their hands in water a lot, such as nurses, hairdressers, and cleaners. This type of contact dermatitis is more likely to happen in people who have suffered from childhood eczema. Allergic contact dermatitis. This type occurs when you develop an allergy to a specific substance that’s been in contact with your skin. Common examples of these include hair dye, cosmetics, and perfumes. It’s unclear why some people who are exposed to these develop dermatitis while others don’t but unlike irritant dermatitis, contact dermatitis doesn’t seem to be more likely in people who had eczema when young. What are the symptoms of contact dermatitis? The commonest symptom is itching of the skin, and this can be very intense and to a level where you can’t stop scratching it. The skin can also become sore and red, with blisters developing that can weep. In contact dermatitis of the hands, there may be painful cracking of the skin that can make it difficult to use your hands normally. The hands are the commonest area where contact dermatitis occurs, followed by the arms, neck and face.

Dandruff is caused by dead skin cells falling off your scalp which can be seen as white-grey flakes on your scalp, in your hair and sometimes on your clothes. It can also cause symptoms of an itchy scalp. It is very common and not linked to hair cleanliness although more flakes may build up with the less you wash your hair. Dandruff is a type of seborrhoeic dermatitis that also causes a red, greasy, flakey rash over the nose and cheeks. In the majority of cases, dandruff can be treated at home. Extreme weather conditions, such as when hot, cold or dry may cause dandruff, and stress can worsen the condition in some people. Dandruff is not contagious.

Dry skin – sometimes called xerosis by doctors - is a condition (not necessarily a disease) where the skin is red, scaly and itchy. The problem is usually worse in autumn and winter, and dry skin is most common on the face, hands, arms and legs. As we age, dry skin becomes more likely. It is not a serious problem usually, but can be uncomfortable and unsightly. Ageing, living in dry, cold or low-humidity climates and bathing or showering frequently make it more likely to occur. It affects both sexes, and is more common in Caucasian skin than those whose skin has a higher oil content, such as with Afro-Caribbean or Mediterranean skin. Dry skin can be intensely itchy. It feels rough and flakes easily. Cracks and redness can form in more severe cases. Children can be particularly at risk, and this may take the form of eczema - where inflammation of the uppermost layer of skin causes dryness, and this is most likely to appear on the insides of elbows or the backs of knees. Eczema may run in families or run alongside asthma or hay fever. Dry skin is a variant of normal skin and is not contagious

Folliculitis is a common condition, where one or several hair follicles become inflamed, presenting as painful red raised bumps that may have a white head (pustule). As you might expect, these occur in hairy areas, such as the scalp, beard, chest, back, buttocks and genital area. They can be deep or superficial.

Hidradenitis suppurativa occurs in areas where there are sweat glands around hair follicles. It is a condition that often affects the armpits but can also affect the groin, under the breasts, and around the anus, as well other areas of the body too. It is a chronic condition that can cause both abscesses and scarring of the skin. The cause of hidradenitis suppurativa is unknown. The symptoms are very painful lumps that range from blackheads to boils, cysts, or channels (called sinus tracts) that contain and sometimes leak pus. As it is a long-term recurrent condition that requires ongoing management it can cause quite an impact on an individual’s everyday life and can lead to depression.

Keratosis pilaris is a very common skin condition, where skin gets bumpy and red, resembling chicken skin or goosebumps. It typically occurs on the upper outer arms and thighs, where hair follicles get blocked with pockets of keratin, a thick tough substance that helps to protect the skin. Bumps can be red, grey or flesh-coloured, and skin feels rough, dry and sometimes itchy. This condition affects up to half of the population, running families and appearing most obviously in adolescence, with improvement usually in adulthood. It is completely harmless, but people become concerned with the appearance.

Melanoma (also known as malignant melanoma) is the most serious type of skin cancer caused by sun exposure. It's serious because the cancer can spread to other organs in the body, so it needs prompt identification and treatment. You can take steps to prevent it, but also keep a watch for any moles or other skin marks that are new, changing or don't look like your other moles. Melanoma is the 5th most common cancer in the UK, with almost 17,000 new cases each year. The number of cases has doubled in the last 30 years, and it can occur at any age.

Molluscum contagiosum are small protruding smooth shiny bumps, often flesh-coloured or pink/red, and distinguished by the dip in the centre of their tip. If squeezed (and we advise not), a semi-solid substance may ooze out. This is not recommended as this liquid contains the molluscum virus that causes the bumps, and as these are highly contagious, squeezing risks spreading to other parts of the body or gifting to friends and loved ones. Molluscum is common and usually seen in children. It causes no harm, but parents or sufferers may be bothered by the appearance, and occasionally, a molluscum may become itchy and irritated, or even infected with bacteria.

A mole is usually a mid or dark brown flat mark (a junctional naevus), or a dome-shaped brown or flesh-coloured bump (a dermal naevus). It should be neither itchy nor bothersome. You may have numerous moles, and they may run in your family. They may have been present for as long as you can remember, or since birth, although new moles can appear throughout childhood and even into your 20s, especially after recent sun exposure. Certain skin types such as those with pale skin, blue eyes and red or blond hair, and who are likely to easily burn, are likely to be more at risk of concerning changes to moles.

This is a condition that mainly affects the corners of the mouth rather than the rest of the lips. The main symptoms include swelling and redness, blistering, and crusting or cracking in the corners of the mouth. It’s also sometimes known as angular stomatitis. It may be painful and can be caused by a number of factors. Some forms of angular cheilitis may be caused by sweat and saliva build-up. This causes changes in pH on the skin and can lead to a fungal infection in the corner of the mouth. There can also be bacterial or viral infection present. It is usually bilateral and symmetrical although occasionally it may affect one side of the mouth only and may sometimes spread to cause impetigo or oral thrush.

Actinic keratoses (or solar keratoses) are small red flakey marks on your skin in response to long-term sun damage. They appear many years after sun exposure on sun-exposed areas such as the top of forehead or crown of the head, tops of ears, forearms, hands and lower legs, and so are more common in older people. They feel like rough patches like sandpaper, and yellow or orange scales can appear that resemble tiny cornflakes. The surrounding skin may be pink or red, and there might other evidence of sun damage such as deep wrinkles, large freckles or brown blotches. They don't usually cause any symptoms beyond a mild itch or soreness, but some people feel self-conscious that they look unsightly.

Acne vulgaris, also known as pimples, acne, spots or zits, is very common, usually starting in the teenage years and continuing up to the age of 30. About 80% of teenagers suffer some degree of acne. Mild untreated acne typically takes several years to settle but severe acne can scar the skin for life if untreated. It coincides with the hormonal changes of puberty, and women may suffer into adulthood with hormonal changes in their menstrual cycle. Hormones affect the amount of oil (sebum) produced by glands next to hair follicles so the skin becomes very greasy, and these follicles then become blocked and inflamed. Acne can cause blackheads, whiteheads or pustules, or more inflamed lesions including red and sore cysts and larger nodules, which are more likely to cause long-term scarring. Acne usually affects the face - the T-zone is typical in teenagers (forehead, nose and chin), or the muzzle distribution in early adulthood, which includes the upper lip, chin, jawline and neck. However it can also affect the back and chest.