Dermatology is the branch of medicine concerned with the diagnosis, treatment and prevention of conditions affecting the skin, hair and nails. A doctor who specialises in this field is known as a dermatologist.
The skin is the body’s largest organ and performs many essential functions. It forms a protective barrier between the body and the external environment, helps regulate body temperature, provides sensation and contributes to immune defence.
Because the skin is visible, changes in its appearance are often among the first signs that something may be wrong. However, dermatology involves considerably more than treating cosmetic concerns.
Dermatologists diagnose and manage thousands of conditions ranging from common problems such as acne, eczema and fungal infections to autoimmune skin diseases and skin cancers. They may also treat conditions involving the scalp, hair, fingernails and toenails.
Some dermatologists additionally practise procedural or aesthetic dermatology, providing treatments for scars, pigmentation, signs of skin ageing and other appearance-related concerns.
This guide explains what dermatology is, what dermatologists do, the conditions they commonly manage and what patients can expect when visiting a dermatologist.
What Does Dermatology Mean?
Dermatology is the medical specialty devoted primarily to the skin and its associated structures, particularly the hair and nails.
Although skin may appear relatively simple from the outside, it is a complex organ containing multiple layers, blood vessels, nerves, glands, hair follicles and immune cells.
Skin conditions can arise because of many different factors, including:
- genetics
- infections
- allergies
- immune system disorders
- hormonal changes
- environmental exposure
- medications
- underlying medical conditions
A dermatologist must therefore understand not only the skin itself but also how conditions elsewhere in the body can affect it.
What Is a Dermatologist?
A dermatologist is a medical doctor who has undergone specialist training in diseases affecting the skin, hair and nails.
Dermatologists see patients across a wide range of ages.
A baby may be brought to a dermatologist because of eczema or a birthmark. A teenager may seek treatment for acne. An adult may require assessment of persistent hair loss or an unusual mole. An older person may need evaluation of a suspicious skin lesion.
Some dermatologists practise general medical dermatology, while others develop particular expertise in areas such as skin cancer, paediatric dermatology, hair disorders, dermatological surgery or aesthetic dermatology.
Understanding the Skin
The skin is generally described as having three major layers:
Epidermis
The epidermis is the outermost layer.
It provides an important protective barrier and contains cells involved in producing keratin and skin pigment.
Dermis
The dermis lies beneath the epidermis.
It contains structures such as collagen, blood vessels, nerves, sweat glands and hair follicles.
Subcutaneous Tissue
Below the dermis is the subcutaneous layer, which contains connective tissue and fat.
Together, these structures allow the skin to perform several essential functions.
What Does the Skin Do?
One of the skin’s most important roles is protection.
It helps protect the body from environmental substances, microorganisms and physical injury while reducing excessive water loss.
The skin also contributes to temperature regulation through sweating and changes in blood flow.
Nerve endings within the skin allow us to detect sensations such as touch, temperature and pain.
The skin also participates in immune function and vitamin D production.
Given these diverse functions, diseases affecting the skin can sometimes have consequences extending beyond appearance.
What Conditions Do Dermatologists Treat?
Dermatology covers an extremely broad range of conditions.
Some are temporary and relatively straightforward to manage, while others are chronic and require long-term medical care.
Common conditions encountered in dermatology include acne, eczema, psoriasis, skin infections, pigmentation disorders, hair loss and skin cancer.
Acne
Acne is one of the most common skin conditions.
It frequently begins during adolescence but can also persist or develop during adulthood.
Acne occurs when hair follicles become blocked by oil and dead skin cells, with inflammation and other biological factors also contributing.
Different types of acne lesions can occur, including:
- blackheads
- whiteheads
- papules
- pustules
- nodules
- cysts
The severity of acne varies considerably.
Mild cases may respond to topical treatments, while moderate or severe acne may require prescription medications.
Early and appropriate management can be particularly important when acne is causing significant inflammation or scarring.
Eczema
Eczema is a broad term describing inflammatory skin conditions.
One of the most common forms is atopic dermatitis.
People with eczema may experience:
- dry skin
- itching
- redness or discolouration
- inflammation
- cracking
- recurrent flare-ups
Atopic dermatitis often begins during childhood, although it can continue into adulthood or occasionally develop later in life.
The condition involves several factors, including abnormalities in the skin barrier and immune system.
Management may involve moisturisers, avoidance of relevant triggers and prescription treatments when necessary.
Psoriasis
Psoriasis is a chronic inflammatory condition involving the immune system and skin.
It can produce well-defined areas of thickened, inflamed or scaly skin.
Commonly affected areas include the scalp, elbows and knees, although psoriasis can occur elsewhere.
Some people with psoriasis also develop joint symptoms associated with psoriatic arthritis.
Because psoriasis is a chronic condition, treatment may involve ongoing management rather than a permanent cure.
Treatment options vary according to severity and can include topical therapies, phototherapy and systemic medications.
Skin Allergies and Contact Dermatitis
Skin can become inflamed after exposure to certain substances.
Contact dermatitis is one example.
Irritant contact dermatitis occurs when a substance directly damages or irritates the skin.
Allergic contact dermatitis occurs when the immune system reacts to a particular substance after sensitisation.
Possible triggers can include ingredients found in personal-care products, metals, occupational materials and other environmental substances.
Identifying the cause can sometimes be challenging.
In selected cases, dermatologists may use patch testing to investigate suspected contact allergies.
Skin Infections
Skin infections can be caused by different types of microorganisms.
Bacterial Infections
Bacteria can cause conditions ranging from relatively localised infections to more extensive inflammation.
Viral Infections
Viral skin conditions include certain types of warts and other viral eruptions.
Fungal Infections
Fungi can infect areas such as the skin, scalp and nails.
Common fungal infections include ringworm and athlete’s foot.
Because different infections can sometimes look similar, establishing the correct diagnosis is important before treatment.
Fungal Nail Infections
Nail disorders are also part of dermatology.
Fungal nail infection can cause nails to become:
- thickened
- brittle
- discoloured
- distorted
However, not every abnormal-looking nail is caused by fungus.
Psoriasis, injury and other conditions can produce similar changes.
A dermatologist may therefore recommend testing before prolonged antifungal treatment in certain circumstances.
Hair Loss
Dermatologists also diagnose and manage hair and scalp disorders.
Hair loss can occur for many reasons.
Common forms include hereditary pattern hair loss, alopecia areata and temporary shedding following certain physiological or medical stresses.
Hair loss can also sometimes be associated with nutritional deficiencies, hormonal changes, medications, scalp disorders or other medical conditions.
Because the causes vary considerably, treatment depends on establishing the likely diagnosis.
Alopecia Areata
Alopecia areata is an autoimmune condition in which the immune system affects hair follicles.
It commonly causes round or oval patches of hair loss, although the extent varies.
Some people experience only a small area of hair loss, while others develop more extensive involvement.
The course can be unpredictable.
Dermatologists may offer different treatments depending on the patient’s age, extent of hair loss and individual circumstances.
Pigmentation Disorders
Skin colour is influenced by melanin, a pigment produced by specialised cells known as melanocytes.
Pigmentation disorders can cause areas of skin to become darker or lighter.
Examples include:
- melasma
- post-inflammatory hyperpigmentation
- vitiligo
- certain sun-related pigmentation changes
The appropriate treatment depends on the underlying cause.
Sun protection is often relevant when managing pigmentation because ultraviolet exposure can worsen certain pigmentary conditions.
Melasma
Melasma produces areas of increased pigmentation, frequently on the face.
Hormonal factors and ultraviolet exposure can contribute to the condition.
Melasma can be persistent and may recur.
Treatment may involve sun protection, topical medications and, in selected cases, procedures.
Because some treatments can themselves cause irritation or pigmentation changes when used incorrectly, professional assessment may be beneficial.
Vitiligo
Vitiligo is a condition in which areas of skin lose pigment because melanocytes are damaged or destroyed.
This results in lighter or white patches of skin.
Vitiligo is not contagious.
The extent and progression vary considerably between individuals.
Treatment can include topical medications, phototherapy and other approaches depending on the patient’s circumstances.
Moles
Moles, medically known as melanocytic naevi, are common skin growths.
Most are benign.
However, changes in a mole or the development of an unusual skin lesion may warrant medical assessment.
People may be advised to seek evaluation when a mole shows significant changes in characteristics such as size, shape, colour or appearance.
A dermatologist can examine suspicious lesions and determine whether additional investigation is required.
Skin Cancer
The diagnosis and treatment of skin cancer are important areas of medical dermatology.
There are several types of skin cancer, including:
- basal cell carcinoma
- squamous cell carcinoma
- melanoma
These cancers behave differently and require different approaches to management.
Melanoma is particularly important because it can become serious if it spreads to other parts of the body.
Early detection can therefore be important.
Not every unusual mole or skin growth is cancerous, but lesions that are new, changing, bleeding, non-healing or otherwise concerning should be assessed by an appropriate healthcare professional.
Skin Biopsy
When a dermatologist cannot determine the exact nature of a skin condition from examination alone, a skin biopsy may be recommended.
During a biopsy, a small sample of skin is removed and sent to a laboratory for examination under a microscope.
There are several types of skin biopsy, and the technique used depends on the lesion and the information required.
Biopsies can help diagnose inflammatory skin diseases, infections and skin cancers.
Dermatological Surgery
Dermatology includes both medical and procedural treatment.
Dermatologists may perform procedures such as:
- skin biopsies
- removal of certain skin lesions
- treatment of some cysts
- cryotherapy
- electrosurgery
- skin cancer surgery
Some dermatologists undertake additional training in advanced dermatological surgery.
The appropriate procedure depends on the diagnosis, location and nature of the condition.
Scars
Dermatologists may also assess and manage scars.
Scars can develop following acne, injury, burns, surgery or inflammatory skin conditions.
Different types of scars require different approaches.
Examples include:
Atrophic scars – depressed scars commonly associated with acne.
Hypertrophic scars – raised scars that remain within the boundaries of the original injury.
Keloids – raised scars that extend beyond the original wound.
Treatment options depend on scar type and may include topical measures, injections, lasers or other procedures.
Complete removal of a scar is not always possible, so treatment often focuses on improving appearance or symptoms.
Aesthetic Dermatology
Some dermatologists also practise aesthetic or cosmetic dermatology.
This area focuses on concerns related to skin appearance rather than treatment of disease alone.
Patients may seek consultation for:
- pigmentation
- acne scars
- uneven skin texture
- fine lines
- wrinkles
- sun-related skin changes
- facial ageing
Treatments can include chemical peels, lasers and other energy-based procedures, injectable treatments and various skin therapies.
Aesthetic treatment should still begin with appropriate assessment because cosmetic concerns can sometimes overlap with medical skin conditions.
Lasers in Dermatology
Laser technology is widely used within certain areas of dermatology.
Different lasers produce different wavelengths of light and therefore interact with different targets within the skin.
Depending on the technology, lasers may be used for selected vascular lesions, pigmentation, hair-related treatments, tattoo removal or skin resurfacing.
There is no single laser that is appropriate for every condition.
Skin type, diagnosis and treatment goals all influence which technology, if any, is appropriate.
Sun Exposure and Skin Health
Ultraviolet radiation from the sun can affect skin in several ways.
Excessive exposure contributes to sunburn, pigmentation changes, premature skin ageing and the development of certain skin cancers.
General sun-protection measures can include:
- seeking shade during periods of intense sunlight
- wearing protective clothing
- using an appropriate sunscreen
- reapplying sunscreen when necessary
People should follow relevant public-health guidance regarding sun protection, particularly when spending prolonged periods outdoors.
Dermatology in Children
Children can experience many skin conditions, including eczema, birthmarks, infections, rashes and genetic skin disorders.
Some dermatologists specialise specifically in paediatric dermatology.
Children’s skin can respond differently to diseases and medications compared with adult skin, making age-appropriate assessment important.
Parents should seek medical assessment when a child’s skin condition is persistent, severe, rapidly worsening or accompanied by other concerning symptoms.
Dermatology in Older Adults
Skin changes naturally with age.
Older adults may experience thinner and drier skin, increased bruising and various benign skin growths.
Cumulative sun exposure also becomes increasingly relevant.
Dermatologists may assess age-related changes as well as skin cancers, persistent rashes, itching and other conditions affecting older patients.
What Happens During a Dermatology Consultation?
A dermatology consultation generally begins with a discussion of the patient’s concerns.
The dermatologist may ask:
- when the problem started
- whether it has changed
- whether it is itchy or painful
- which treatments have already been tried
- what medications the patient takes
- whether allergies are present
- whether there is a family history of skin conditions
The doctor then examines the affected skin.
Depending on the condition, examination of the scalp, hair or nails may also be appropriate.
Some lesions may be examined using a dermatoscope, a specialised magnifying device that allows closer inspection of skin structures.
Further testing may occasionally be required.
When Should Someone See a Dermatologist?
There are many possible reasons to seek dermatological assessment.
These can include:
- persistent acne
- severe or recurrent eczema
- psoriasis
- unexplained rashes
- chronic itching
- significant hair loss
- nail abnormalities
- pigmentation changes
- suspicious or changing moles
- non-healing skin lesions
- recurrent skin infections
- significant scarring
A GP can manage many common skin problems and may refer patients to a dermatologist when specialist evaluation is appropriate.
Skin Conditions and Other Diseases
The skin can sometimes provide clues about conditions affecting other parts of the body.
Certain autoimmune diseases, infections, hormonal disorders, nutritional deficiencies and medication reactions can produce visible skin changes.
This is one reason dermatology overlaps with many other medical specialties.
Dermatologists may work with:
- rheumatologists
- allergists and immunologists
- endocrinologists
- oncologists
- infectious disease specialists
- plastic surgeons
- general practitioners
- paediatricians
Complex conditions can therefore require multidisciplinary care.
Medical Dermatology Versus Aesthetic Medicine
Although the two areas can overlap, medical dermatology and aesthetic medicine are not identical.
Medical dermatology focuses on diagnosing and treating diseases of the skin, hair and nails.
Aesthetic medicine primarily focuses on improving appearance.
For example, treating severe inflammatory acne is primarily a medical issue. Treating the remaining acne scars after the active disease is controlled may have a larger aesthetic component.
Similarly, evaluating a changing pigmented lesion is a medical matter rather than simply a cosmetic one.
Correct diagnosis should generally come before cosmetic treatment when the nature of a skin lesion is uncertain.
Why Is Dermatology Important?
Skin conditions are sometimes dismissed as being “only cosmetic.”
In reality, dermatological disease can substantially affect comfort, sleep, confidence and quality of life.
Severe eczema can cause intense itching and interfere with sleep. Acne can produce permanent scarring. Psoriasis can be associated with disease beyond the skin. Some skin cancers can become serious if not identified and treated appropriately.
Dermatology therefore combines preventive healthcare, medical diagnosis, medication, surgery and procedural treatment.
Caring for the Skin
There is no universal skincare routine that is ideal for every person.
Skin differs according to age, genetics, environment and medical conditions.
However, basic principles generally include gentle cleansing, maintaining the skin barrier, appropriate moisturisation where necessary and protecting the skin from excessive ultraviolet exposure.
People with specific skin diseases may require substantially different skincare routines or prescription treatments.
Using numerous products is not necessarily better.
In some individuals, excessive cleansing, exfoliation or frequent use of active ingredients can irritate the skin barrier.
When Is a Skin Condition an Emergency?
Most dermatological conditions do not require emergency care, but some situations can be urgent.
Examples can include a rapidly spreading rash accompanied by severe illness, severe blistering or peeling of the skin, significant facial swelling with breathing difficulty or signs of a serious allergic reaction.
A rapidly progressing infection associated with severe pain, fever or systemic illness may also require urgent medical attention.
Potential emergencies should be assessed promptly rather than waiting for a routine dermatology appointment.
Dermatology Across Different Stages of Life
Skin health changes considerably throughout life.
Infancy and childhood may involve eczema, birthmarks and childhood skin infections.
Adolescence commonly introduces concerns such as acne and increased oil production.
Adulthood may involve inflammatory conditions, pigmentation, hair loss and occupational or environmental skin problems.
Later adulthood brings age-related changes, accumulated sun damage and increasing importance of evaluating suspicious skin lesions.
Dermatology consequently serves patients from infancy through old age.
Conclusion
Dermatology is the branch of medicine dedicated to the diagnosis, treatment and prevention of diseases affecting the skin, hair and nails.
A dermatologist is a specialist medical doctor trained to manage a broad range of conditions, from common skin problems to complex inflammatory diseases and skin cancers.
Common reasons for visiting a dermatologist include acne, eczema, psoriasis, hair loss, pigmentation disorders, fungal infections, nail conditions, suspicious moles, persistent rashes and skin growths.
Dermatology can involve both medical and procedural care. Treatment may include topical medications, oral medications, injections, phototherapy, minor surgical procedures, lasers and other therapies depending on the condition.
Some dermatologists also provide aesthetic treatments for concerns such as acne scars, pigmentation, skin texture and signs of ageing.
However, the fundamental purpose of dermatology extends well beyond appearance. The skin is a complex and essential organ, and changes in the skin can sometimes provide important information about overall health.
Persistent, unusual, rapidly changing or concerning skin problems should therefore be appropriately assessed rather than simply treated as cosmetic concerns.
This article is intended for general educational purposes only. It does not constitute personalised medical advice, diagnosis or treatment. Anyone concerned about a skin, hair or nail condition should consult an appropriately qualified healthcare professional. Severe or rapidly worsening symptoms should receive prompt medical attention.