A dermatologist doctor is a specialist in the diagnosis, prevention, treatment, and management of problems related to skin, nails, and hair. They also provide advice in taking care of normal skin and keeping it healthy.

You can consult a dermatologist if you have:
Severe acne
Dryness of skin
Hair loss
Scars
Fungal infections
Skin allergies
Eczema
Lupus erythematosus (an inflammatory autoimmune disease)
Psoriasis (scaly, red patches on the skin)
Ingrown toenails
Rosacea (redness on the face)
Shingles
Warts
Diagnosis of skin cancer

A dermatologist is trained for laser treatment of skin problems. Hence, a dermatologist can be consulted if you wish to do laser treatment for problems such as reducing scars or wrinkles, removing unwanted hair, tattoos, or skin discolourations, decreasing acne, improving the tone of the skin, and restoring skin collagen.

Some of the services provided by dermatologist include:
Medications that are applied externally, injected, or those taken orally
Skin biopsies
Injections such as botox or fillers
Cryotherapy
Micro-dermabrasion
Laser surgery
Chemical peels
Restoration and elimination of excess hair
Excision surgery
Ultraviolet light therapy
Skin grafting
Liposuction

A cosmetologist is an expert in beautifying hair, nails, and skin. They involve in personal care services such as botox, fillers, liposuction, etc that help improve aesthetics. A dermatologist is a healthcare professional who helps in diagnosing and providing treatment to disorders of the hair, nails, and skin such as eczema, fungal infections, and dermatitis.