Alopecia is a condition relating to the autoimmune system, causing hair to come out in small clumps. The condition can affect people in different ways; some people may lose hair in just a few areas, while others may lose more. In some cases, hair can grow back for good, but some people find that it falls out again. Alopecia areata is the most common form, though there are other more rare types.

This is an abnormality in the hair shaft which causes strands of hair to have a knotty appearance; like the knots on a bamboo stalk. It’s sometimes referred to as Trichorrhexis Invaginata. The condition is typically associated with a rare hereditary disease called Netherton syndrome, which also affects the skin.  

This is a skin condition that’s common in babies, where greasy or yellow crusts form on the scalp, and sometimes other areas of the body. It’s considered a harmless condition, which usually clears up on it’s own and doesn’t cause any itching, pain or discomfort.

Contact dermatitis is a type of eczema which can occur when the skin comes into contact with an irritant or allergen. Symptoms can include redness, itching and cracking of the skin. This can affect any part of the body, including the scalp, but is most common on the hands and face.

Dandruff is a very common condition affecting the scalp. White or grey flakes of skin appear in the hair and the scalp can become itchy. Much like seborrhoeic dermatitis, it is caused by an overgrowth of the naturally-occurring yeast malassezia, though it is considered a more mild variant.

This skin rash appears as a result of injury or inflammation of the blood capillaries. It can happen in response to a drug, disease or infection. Erythema may appear as part of another scalp condition, for example dandruff or seborrhoeic dermatitis. 

Folliculitis is a common condition, often caused by a bacterial or fungal infection, which results in inflammation of the hair follicles. Initially, it can appear as small red bumps, or whiteheads, but can develop into sores with time. In more severe cases, the infection can cause scarring and hair loss.

Granuloma annulare is a degenerative skin condition, which comes in several forms, affecting different parts of the body. The subcutaneous, or ‘under the skin’, form of the condition can present as a single, painless mass on the scalp, arms or legs, and is more likely to affect children. Other forms can affect more than one body part at once, including the forehead, abdomen and neck.

Head lice are small insects which are passed on through head-to-head contact, typically affecting young children and their families. They can be hard to spot, but you may feel like something is moving in your hair.

This skin condition causes dry, thick scaling of the skin that is rough to the touch. There are several different types of ichthyosis, some of which are inherited at birth and others which can develop during adulthood. Acquired ichthyosis usually relates to an underlying condition, such as underactive thyroid or kidney disease. The condition can also affect the scalp, leading to dryness and scaling.

A keloid scar is a raised scar which can be pink, red or darker than the surrounding skin. Keloid scars usually develop after minor skin damage, for example after a piercing. They are more common on the chest, shoulders, head and neck areas and it’s uncommon for the scars to occur on the scalp area alone.

This skin rash can affect various parts of the body, including the inside of the mouth. Symptoms can include shiny, raised patches on the skin which are a purple-red in colour. In the scalp area, you may notice bald patches. The rash can be itchy, but it isn’t contagious and in many cases clears over time.

Widely known as heat rash or prickly heat, this skin condition causes a rash of small, red bumps to form on the skin, as a result of the sweat glands becoming blocked. It can be itchy, uncomfortable and sometimes ‘prickly’. It’s more common in hot climates. In adults, the condition often affects areas of friction with clothing, including the upper torso, scalp, neck and flexures.

Nevus sebaceous is a rare type of birthmark, thought to be caused by genetics and most often found on the scalp. Despite being classified as a tumour of the hair follicle, it is benign. It’s appearance will change with age; in children it appears as a smooth yellow or orange patch, whereas in adults it has been likened to a patch of thick warts.

It’s natural for the scalp to produce oil in order to protect and hydrate the hair. However the amount of oil produced can vary and in some cases an overproduction of oil can lead to a greasy scalp. This can be due to genetics, overwashing the hair or even underlying skin conditions.

Psoriasis is a skin condition that presents as red patches of skin with silver scales. In some cases, the skin can become inflamed and cracked. Psoriasis develops as a result of faster skin cell production, which leads to excess skin being formed. It’s mostly commonly found in areas such as the knees, elbows, scalp and lower back, but can occur in many places on the body.

Pityriasis amiantacea presents as yellow or silver scales which develop on the hair shafts and can bind the hair down. It is linked to a number of conditions, including scalp psoriasis, seborrhoeic dermatitis and tinea capitis. When no underlying condition is identified, it’s classed as idiopathic pityriasis amiantacea. This form often clears up completely with treatment, but when linked to an underlying chronic condition, the symptoms may persist or reappear.

This is a common condition which leads to redness in the skin. Over time, small blood vessels can become visible. Although it mainly affects the face, it sometimes appears on the neck and scalp too. It occurs more often in women, but will appear more pronounced in men. It’s thought that a family history of rosacea can increase the likelihood of it developing.

Another autoimmune skin condition which can affect the scalp is seborrhoeic dermatitis. The symptoms appear in areas of the body where there are oil-producing sebaceous glands. The condition is triggered by an overgrowth or overreaction to the naturally-occurring yeast malassezia, and presents as redness and scaling in greasy areas. It’s considered to be the more severe form of dandruff.

Also known as scalp ringworm, tinea capitis is a fungal infection, which affects the scalp and hair. The condition can cause hair loss, dryness, scaling and itching. It most commonly occurs between the ages of three and seven years, though it can also occur in adults. It’s a contagious infection and can spread through contact with an infected person or shared items, like brushes, combs and towels.

Hives, sometimes referred to as urticaria, can occur anywhere on the body, including the scalp. They appear as red, itchy bumps and tend to come and go within a few hours. Hives can develop when there is a high level of histamine in the skin. This reaction can be triggered by a number of things, including food, plants, insect bites, chemicals, dust and sunlight. Stress has also been known to trigger hives.

Vitiligo is a long-term skin condition caused by a lack of melanin in the skin. It can start as a pale patch of skin which gradually turns white with time. It normally affects areas such as the face, the neck, the hands and areas which have skin folds, but is also known to develop on the scalp too. In cases like this, the hair in the affected area may turn white or grey.

There are many different types of warts, some developing in different areas of the body. They are spread by person-to-person contact, or indirect contact with shared items, and are caused by a virus, known as HPV, which infects the top layer of skin. Pedunculated warts are known to appear on the head, neck and scalp and are shaped like a cauliflower, whereas other types of warts, like the common wart, can appear in places like the fingers, hands, elbows and knees.

Candidiasis, also known as a yeast infection, is caused by the yeast candida albicans. Skin typically has a small amount of harmless yeasts, but an overgrowth can sometimes cause infections. These can develop anywhere around the body, including on the scalp, and can be due to an imbalance in the skin’s natural environment, for example due to diet, stress or other medical conditions. Warm, moist conditions can also contribute to a yeast infection.