A dermatologist is a medical specialist in the diagnosis, treatment, and prevention of diseases that affect the skin, hair, nails, and some mucous membranes, such as the mouth and genital region.
It treats people of all ages, from newborns to the elderly. Although dermatology is often associated with acne, moles, or cosmetic treatments, it is actually a very broad medical specialty, capable of addressing everything from minor problems to autoimmune diseases, complex infections, and skin cancer. American Academy of Dermatology Association, 2022
What training does a dermatologist have?
To become a dermatologist, one must first complete medical school and obtain a medical degree. Afterward, the physician must enter a formal residency or specialization program in Dermatology. In Costa Rica, the Dermatology Specialization at the University of Costa Rica lasts a total of four years. Its training comprises a first year focused on Internal Medicine and three years dedicated specifically to learning Dermatology.
To be admitted to the program, applicants must hold a Bachelor of Medicine and Surgery degree from a recognized university and be registered with the College of Physicians and Surgeons of Costa Rica. They must also pass the selection process established for medical specialties. University of Costa Rica, 2026
During residency, the doctor receives training in areas such as:
Diseases of the skin, hair, nails and mucous membranes.
- Pediatric dermatology.
- Skin cancer and dermato-oncology.
- Dermatological surgery.
- Dermatopathology or microscopic study of skin diseases.
- Skin infections.
- Autoimmune and blistering diseases.
- Allergies and drug reactions.
- Diagnostic and therapeutic procedures.
- Aesthetic dermatology.
The Costa Rican program aims to train specialists competent in clinical diagnosis and with surgical skills to treat diseases that require it. It also includes training in research, teaching, and prevention. University of Costa Rica, 2026
A dermatologist is not simply someone who has taken courses on skin care or cosmetic procedures. They are a medical doctor who, after graduating from medical school, completes several additional years of specialized training.
What conditions does a dermatologist treat?
Dermatologists can diagnose and treat a wide variety of diseases of the skin, hair, nails, and mucous membranes. The American Academy of Dermatology notes that the specialty encompasses more than 3.000 different conditions. American Academy of Dermatology Association, 2022
The main reasons for consultation include the following.
Acne and inflammatory diseases
The dermatologist treats common conditions such as:
- Acne.
- Rosacea.
- Atopic dermatitis.
- Contact dermatitis.
- Seborrheic dermatitis.
- Psoriasis.
- Urticaria.
- Lichen planus.
- Hidradenitis suppurativa.
- Bullous diseases, such as pemphigus and pemphigoid.
These diseases can cause itching, pain, peeling, redness, blisters, or persistent lesions. Some can also significantly affect sleep, self-esteem, and quality of life.
Skin infections and infestations
The dermatologist also diagnoses and treats diseases caused by:
- Fungi and yeasts.
- Bacteria
- Viruses, such as herpes, molluscum contagiosum, and warts.
- çParasites, such as scabies, pediculosis and cutaneous larva migrans.
Although some infections may seem simple, it is important to correctly establish their cause, since not all reddish, scaly or itchy lesions correspond to an infection.
Hair and scalp problems
Dermatology includes the study of diseases of the hair and scalp, including:
- Hair loss.
- Androgenetic alopecia.
- Alopecia areata.
- Scarring alopecias.
- Seborrheic dermatitis.
- Scalp infections.
- Hair shaft alterations.
Hair loss can have hereditary, inflammatory, hormonal, nutritional, autoimmune, or medication-related causes.
Nail diseases
Changes in the nails can also be evaluated by a dermatologist. Some examples include:
- Fungal nail infections.
- Brittle or deformed nails.
- Ingrown toenails.
- Inflammation around the nails.
- Tumors under or around the nail.
- Nail alterations associated with psoriasis and other diseases.
In certain cases, a change in the color or shape of a nail may be the first sign of a skin or internal disease.
Spots and pigmentation disorders
The dermatologist can evaluate dark, light, or reddish spots, including:
- Melasma.
- Vitiligo.
- Sunspots.
- Hyperpigmentation after inflammation.
- Guttate hypomelanosis.
- White spots of different causes.
- Congenital pigmentation disorders.
Before treating a blemish as a purely cosmetic problem, it is important to determine its cause and rule out an injury that requires medical attention.
Moles and skin cancer
One of the most important roles of a dermatologist is to examine moles and other lesions that could be indicative of skin cancer. Among the conditions they can diagnose and treat are:
- Actinic keratoses.
- Basal cell carcinoma.
- Squamous cell carcinoma.
- Melanoma.
- Atypical moles.
- Cutaneous lymphomas.
- Other benign and malignant skin tumors.
To evaluate these lesions, the dermatologist may perform a complete skin examination, use a dermatoscope, or take a biopsy. A biopsy involves removing a small sample for microscopic examination.
Does the dermatologist perform surgeries?
Yes. Dermatology is a specialty. clinical-surgical.
In addition to prescribing medications and recommending skin care, a dermatologist may perform procedures such as:
- Skin biopsies.
- Mole removal.
- Removal of cysts and benign tumors.
- Skin cancer surgery.
- Cryotherapy.
- Electrosurgery.
- Nail surgery.
- Infiltrations.
- Scar treatment.
- Mohs micrographic surgery.
Mohs surgery is a specialized technique used primarily for certain skin cancers. It allows for examination of the margins during the procedure and removal of the tumor while preserving as much healthy skin as possible.American Academy of Dermatology Association, 2021).
Some procedures can be performed in the office with local anesthesia, while others require surgical facilities or the involvement of professionals from different specialties.
Does dermatology also include cosmetic treatments?
Yes. Cosmetic dermatology is part of the specialty. Due to their knowledge of the skin and the structures beneath it, dermatologists can assess and treat concerns such as:
- Wrinkles and signs of aging.
- Stains
- Acne scars.
- Loss of facial volume.
- Sun damage.
- Visible blood vessels.
- Uneven skin texture.
- Hair loss.
- Benign lesions that affect appearance.
Depending on the patient's needs and the professional's specific training, the dermatologist can perform procedures such as botulinum toxin, fillers, chemical peels, lasers, microneedling, and other energy-based treatments.
Although their goal may be to improve appearance, these are medical procedures. Performing them safely requires knowledge of anatomy, identifying potential contraindications, selecting the right patient, and knowing how to prevent and treat complications. American Academy of Dermatology Association, 2026
Before treating a lesion for cosmetic purposes, it is necessary to establish its diagnosis. A spot that seems harmless, for example, could correspond to a precancerous lesion or skin cancer.
The skin can reflect what is happening inside the body
The skin doesn't function in isolation. Some internal diseases can produce visible manifestations on it. Skin changes may be related to:
- Autoimmune diseases.
- Hormonal alterations
- Diabetes.
- Liver or kidney diseases.
- Circulatory disorders.
- Drug reactions.
- nutritional deficiencies.
- Systemic infections.
For this reason, the dermatologist does not limit themselves to observing the surface of the skin. They also consider the symptoms, medical history, medications used, and the person's overall health.
When necessary, they can order laboratory tests, imaging studies, cultures, allergy tests, or biopsies. They can also work in conjunction with professionals in internal medicine, rheumatology, oncology, infectious diseases, allergology, surgery, and other specialties.
When is it advisable to consult a dermatologist?
It is advisable to request a dermatological evaluation when the following appear:
- A mole that changes size, shape, or color.
- An injury that grows, bleeds, or does not heal.
- A persistent or recurring outbreak.
- Intense itching without a clear cause.
- Significant hair loss.
- Significant changes in the nails.
- Acne that leaves spots or scars.
- A skin infection that is not getting better.
- A skin disease that affects sleep or quality of life.
- An aesthetic concern that requires medical diagnosis and treatment.
It can also be used preventively to check moles, assess sun damage, receive sun protection recommendations, or determine which products and procedures are appropriate for each person.
Botton line
A dermatologist is a medical doctor specializing in the health of the skin, hair, nails, and mucous membranes. Their training enables them to diagnose and treat common illnesses, complex conditions, infections, autoimmune diseases, and skin cancer.
Dermatology is a clinical-surgical specialty that also includes diagnostic procedures, skin surgery, and cosmetic treatments. Consulting a dermatologist allows for a comprehensive evaluation and the selection of appropriate, safe, and evidence-based treatments.
Bibliography and sources
- University of Costa Rica. Specialization in Dermatology: academic-professional profile, requirements and duration [Internet]. San José: Postgraduate Studies System, University of Costa Rica; 2026 [cited 25 Jul 2026]. Available from: https://www.sep.ucr.ac.cr/posgrado-especialidades-medicas-oferta-academica/dermatologia
- American Academy of Dermatology Association. What is a dermatologist? [Internet]. Rosemont: American Academy of Dermatology Association; 2022 [cited Jul 25, 2026]. Available in: https://www.aad.org/public/fad/what-is-a-derm
- Mayo Clinic. Dermatology: conditions treated [Internet]. Rochester: Mayo Foundation for Medical Education and Research; 2024 [cited Jul 25, 2026]. Available in: https://www.mayoclinic.org/departments-centers/dermatology/sections/conditions-treated/orc-20420534
- American Academy of Dermatology Association. What is Mohs surgery? [Internet]. Rosemont: American Academy of Dermatology Association; 2021 [cited Jul 25, 2026]. Available in: https://www.aad.org/public/diseases/skin-cancer/what-is-mohs-surgery
- American Academy of Dermatology Association. Your safety: cosmetic treatments [Internet]. Rosemont: American Academy of Dermatology Association; 2026 [cited Jul 25, 2026]. Available in: https://www.aad.org/public/cosmetic/safety
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