10 symptoms that make it worth going to a dermatologist

Content author: physician. Katarzyna Przekazińska-Boager · Editorial work: Editorial team of Wyspa Medycyny Przyjaznej · Medical review: lek. Katarzyna Przekazińska-Boager · Date of creation: 07.08.2026 · Date of review: 07.08.2026 · Updated: 07.08.2026

The article is educational and does not replace a dermatological examination. An extensive rash with fever, blisters or involvement of the mucous membranes, swelling of the face, lips or tongue, shortness of breath, as well as rapidly spreading redness with fever and malaise require immediate medical attention. A lesion that does not heal for several weeks requires urgent consultation, even if it does not hurt.

The most important information at a glance

• The most common reason for a visit is because the lesion is changing - it is growing, darkening or looking different than before.
• A lesion that does not heal for several weeks requires evaluation regardless of whether it hurts.
• Persistent itching without a visible rash may be a symptom of systemic diseases, not only skin diseases.
• A rash that persists despite treatment is a signal to verify the diagnosis, not to change the cream.
• A dark, longitudinal strip on the nail plate always requires medical evaluation.
• Hair loss may be a symptom of deficiencies, thyroid diseases or the effects of medications - it requires diagnosis, not just shampoos.
• Acne is worth treating early because acne scars are much more difficult to treat than the acne itself.
• Recurrent inflammatory skin lesions can be controlled, even when the disease is chronic.
• Several dermatological situations are emergencies requiring attention within hours.
• Postponing the appointment does not change the diagnosis - it only changes the moment at which it is diagnosed.

Find out more about the specialist

Doctor. Katarzyna Przekazińska-Boager works at the Island of Friendly Medicine in Gdańsk. He assesses and treats skin lesions, including examining moles. The most common scenario in the office looks like this: the patient comes in with one lesion, and the most important thing is something that he did not notice himself - so it is worth examining the skin in more detail than just in one place.

Meet the doctor. Katarzyna Przekazińska-Boager

First, what cannot wait

Most skin problems are planned. However, a few situations require immediate help:

• Extensive rash with fever, especially after starting a new medication,
• Blisters, peeling of the epidermis or painful erosions on the skin,
• Changes on the mucous membranes - in the cavity mouth, on the lips, conjunctiva or genitals - accompanying a rash,
• Swelling of the lips, tongue, face or throat, feeling of tightness in the throat,
• Shortness of breath, wheezing, dizziness after contact with an allergen or taking a medicine,
• Rapidly spreading, painful redness with fever and malaise,
• Extensive sunburn with blisters, fever and weakness,
• Sudden, very severe rash in a child with fever and deterioration of the general condition.

The first point requires special vigilance. A rash that appears after starting a new drug, especially with fever, involvement of mucous membranes or blisters, may be the beginning of a serious drug reaction - a situation in which time is of the essence and immediate discontinuation of the drug under medical supervision.

10 symptoms worth seeing a dermatologist

Below is an elaboration of those points that in practice are most often downplayed or treated incorrectly.

1–3. Changes to watch for

A birthmark that is changing. The most important feature is not the size or color, but change over time. A mole that grows, darkens, changes shape, begins to itch or bleeds, requires dermatoscopic evaluation. A simple rule is also helpful: birthmarks in one person are usually similar to each other - the one that clearly stands out from the rest deserves to be looked at.

Non-healing morning. This symptom is seemingly trivial and therefore most often ignored. An ordinary wound heals once and does not come back. A lesion that bleeds or scabs over in the same place again every few weeks is suspicious - and it doesn't have to hurt. Lack of pain is the rule here, not an argument for waiting.

Rough, scaly patch. It is often easier to feel than to see. On skin exposed to the sun - face, ears, bald patches, forearms - it may be actinic keratosis, i.e. a precancerous lesion. Months of applying a moisturizer usually doesn't change anything, because the problem is not dryness.

4. Itching - a symptom that does not always come from the skin

Itching is one of the most troublesome symptoms in dermatology, and at the same time one of the most misleading. When accompanied by a rash, the diagnostic direction is usually clear. The problem begins when the skin looks normal but still itches - sometimes so intensely that it prevents sleep.

Itching without skin lesions may be a symptom of systemic diseases: liver and bile duct diseases, chronic kidney disease, thyroid disorders, iron deficiency anemia, diabetes, and sometimes diseases of the hematopoietic system. It may also result from the medications you take.

Therefore, in the case of persistent itching without an identifiable cutaneous cause, basic tests are performed to assess the function of the liver, kidneys, thyroid gland and morphology. This is a situation where topical treatment alone is not enough - and another moisturizing cream only delays the diagnosis.

Separately, it is worth mentioning itching in older people, often associated with dry skin. Dryness may indeed be the cause, but before accepting it, it is worth ruling out the others.

5. Rash - When to stop waiting

A rash is not a diagnosis, but a symptom - and there are dozens of causes: from allergic reactions and infections, through inflammatory skin diseases, to drug reactions. Therefore, symptomatic treatment alone without determining the cause may be ineffective.

A rash that:

• persists despite treatment or recurs after its completion,
• it spreads quickly,
• appeared after starting a new drug,
• affects the mucous membranes,
• creates blisters or oozing erosions,
• occurs with fever or malaise,
• it itches very much and prevents sleep,
• it affects a child and has an unusual course.

Practical advice that really shortens the diagnostic process: before the visit, it is worth taking photos of the rash, especially if it changes its appearance from day to day or appears periodically. Very often, on the day of the visit, the skin looks different than when it was at its worst.

6–7. Acne and hair loss

Acne. The most common mistake is procrastination - trying new products for a year or two and only coming forward when scars appear. This is important because Acne scars are much more difficult to treat than acne itself. Therefore, early implementation of treatment is also the prevention of permanent consequences.

It is also worth remembering that not all facial changes that resemble acne are acne-like. Rosacea, perioral inflammation and reactions to cosmetics look similar but require completely different treatment - and some preparations used to treat acne may worsen them.

Hair loss. It's a symptom, not a disease - and that's why shampoos tend to be ineffective. The cause may be iron deficiency, thyroid disease, hormonal disorders, previous infection or severe stress, deficiencies after a restrictive diet, as well as the effects of medications. Hair loss after an illness may be delayed for several months, which makes it difficult to identify the cause.

Therefore, diagnostics usually begins with an interview, assessment of the scalp and laboratory tests, and not with the selection of a preparation. It is worth reporting early - with some forms of hair loss, time is important for the results of treatment.

8. Nails - a symptom that should not be overlooked

Nail changes are most often mild: mycosis, consequences of trauma, changes in the course of psoriasis, damage after cosmetic treatments. However, there is one symptom that requires separate treatment.

A dark, longitudinal strip running along the nail plate always requires medical evaluation. Most often, it has a benign cause, but it may also be a symptom of a pigmented lesion requiring diagnostics. It is particularly disturbing when the band widens, darkens, changes shape, covers the nail fold or affects a single nail in an adult.

It is also worth knowing that nail fungus cannot be diagnosed by eye. Many other diseases present a similar picture, and antifungal treatment is long-lasting - so it is worth confirming the diagnosis with a test before starting it.

Before a nail visit, it is worth removing nail polish, including hybrid nail polish - without it, it is simply impossible to assess the nail plate.

9–10. Chronic diseases and infectious lesions

Recurrent inflammatory skin lesions. Atopic dermatitis, psoriasis and seborrheic dermatitis are chronic diseases - and this word can be discouraging for patients. However, it is worth understanding what it means: not the lack of treatment options, but the need for long-term treatment. The goal is to control the disease, prolong disease-free periods and quickly control exacerbations.

The biggest problem in this group is emergency treatment: starting the preparation during an exacerbation and abandoning it as soon as the skin improves. This pattern leads to continuous circulation between relapses. Constant basic care is as important as proper treatment.

Warts and infectious lesions. Viral warts, commonly called warts, and molluscum contagiosum are benign but infectious lesions - both for the environment and for the patient himself. The most common mistake is cutting and picking on your own, which leads to spreading to the adjacent skin. These changes are also worth assessing to confirm that they are indeed changes.

How to prepare for your visit

• Remove your makeupif the problem concerns your face.
• Remove nail polish, including hybrid nail polish if nails are to be assessed.
• Do not apply lotions or oils on the day of the examination to the area to be assessed.
• Take photos of the lesionsif they look different than when they were at their worst.
• Prepare a list ofmedications, including over-the-counter medications and supplements.
• Note down what you have already used - what preparations, for how long and with what effect.
• Consider the course of: since when, what intensifies, what alleviates, whether there is any seasonality.
• Dress in a way that easily reveals the area requiring assessment.

The most underrated point is the penultimate one. Information that a given ointment has been used for three weeks without any effect is as valuable to the doctor as the appearance of the lesion itself - because the lack of response to a specific treatment in itself guides the diagnosis.

The most common myths

• "If it doesn't hurt, it's nothing dangerous." No. Most skin cancer lesions do not hurt at an early stage.
• "Just smear the rash." No. Rash is a symptom and treatment depends on the cause.
• "Itching always comes from the skin." No. It may be a symptom of liver, kidney, thyroid disease or anemia.
• "You have to wait for acne, it will go away on its own." Not worth it. Acne scars are much more difficult to treat than acne itself.
• "Shampoo is enough for hair loss." No. This is a symptom that requires determining the cause, often with blood tests.
• "Nail fungus is visible at first glance." No. Many diseases present a similar picture; the treatment is long, so it is worth confirming the diagnosis.
• "The application will assess my birthmark." No. It does not replace dermatoscopy or medical examination.
• "Chronic disease means there is nothing you can do." No. It means long-term treatment aimed at controlling symptoms.

Do you recognize any of these symptoms?

Most skin lesions have a benign cause and are treatable - but testing, not waiting, will determine the outcome. If you experience sudden symptoms, go to the emergency department immediately.

Dermatological consultation at the Island of Friendly Medicine in Gdańsk

At the Island of Friendly Medicine, doctor. Katarzyna Przekazińska-Boager consults patients with skin lesions and dermatological ailments. The visit includes an interview, skin assessment, if necessary, a dermatoscopic examination and determination of further proceedings: treatment, observation or in-depth diagnostics.

Some problems require cooperation with other specialists - persistent itching without skin lesions, systemic hair loss or suspected internal diseases. The current scope of services, availability of dates, prices and rules of preparation for the visit should be confirmed during registration.

Find out more about the medicine. Katarzyna Przekazińska-Boager Dermatoscopy

What to ask during the visit?

• What is causing my symptoms?
• Do I need a dermatoscopy or other examination?
• Do I need blood tests?
• Could one of my medications be responsible for these changes?
• How long should I follow the recommended treatment?
• How long should it take for me to notice improvement?
• What to do if symptoms return after treatment?
• What basic care does my skin need?
• Should I have my whole skin looked at?
• How often should I check myself?
• Does the problem require consultation with another specialist?
• What should I worry about before my next visit?

FAQ - when to go to a dermatologist

When to go to a dermatologist?

When the skin lesion changes, does not heal for several weeks, when the rash persists despite treatment, when itching is persistent, hair loss, nail changes or when anything on the skin causes concern.

Which symptom is the most alarming?

A lesion that does not heal for several weeks and a mole that clearly changes over time. In both cases, the absence of pain is typical and should not be reassuring.

When does a rash require immediate attention?

When accompanied by fever, blisters, skin peeling, involvement of mucous membranes, facial swelling or shortness of breath, or when it appears after starting a new medicine.

Does itching without a rash require diagnosis?

Yes. Persistent itching on otherwise normal skin may be a symptom of liver, kidney, thyroid disease or anemia and requires basic tests.

When to treat acne?

The sooner the better. Acne scars are much more difficult to treat than acne itself, so early treatment also prevents permanent consequences.

What to do if you experience hair loss?

Seek a consultation instead of looking for a preparation. Hair loss is a symptom and may be caused by deficiencies, thyroid diseases, hormonal disorders or medications - so diagnosis begins with an interview and tests.

Is a dark stripe on the nail dangerous?

Most often it has a benign cause, but always requires medical evaluation. Especially when it widens, darkens, covers the nail fold or affects a single nail in an adult.

How to prepare for the visit?

Remove makeup, remove nail polish when assessing the nail plate, do not use lotions on the day of the examination, take a list of medications and information about previous treatment and its effects.

Is it worth taking photos of the changes?

Yes, especially if the rash changes appearance from day to day or appears periodically. On the day of your visit, your skin often looks different than when it was at its worst.

Does a dermatologist only deal with skin lesions?

No. The scope also includes hair and nail diseases, and some skin symptoms require systemic diagnostics and cooperation with other specialists.

Can chronic skin diseases be cured?

The aim of treatment is to control the disease: prolonging periods without changes and quickly controlling exacerbations. Constant basic care is as important as proper treatment.

Who works at WMP?

On the WMP website, MD. Katarzyna Przekazińska-Boager sees patients with skin lesions requiring assessment and treatment. The scope of services and availability of dates are confirmed by registration.

Sources

• Island of Friendly Medicine, MD. Katarzyna Przekazińska-Boager: https://www.wyspamedycynyPrzyjaznej.pl/pl/katarzyna-przekazinska-boager
• DermNet, Dermatoscopy: https://dermnetnz.org/topics/dermatoscopy
• DermNet, Pruritus: https://dermnetnz.org/topics/itch
• DermNet, Acne vulgaris: https://dermnetnz.org/topics/acne-vulgaris
• DermNet, Longitudinal melanonychia: https://dermnetnz.org/topics/longitudinal-melanonychia
• DermNet, Drug eruptions: https://dermnetnz.org/topics/drug-eruptions
• NHS, Itchy skin: https://www.nhs.uk/conditions/itchy-skin/
• NHS, Acne: https://www.nhs.uk/conditions/acne/
• NHS, Hair loss: https://www.nhs.uk/conditions/hair-loss/
• NHS, Atopic eczema: https://www.nhs.uk/conditions/atopic-eczema/
• NHS, Psoriasis: https://www.nhs.uk/conditions/psoriasis/
• NICE, Suspected cancer: recognition and referral (NG12): https://www.nice.org.uk/guidance/ng12
• British Association of Dermatologists, patient information: https://www.bad.org.uk/patient-information-leaflets/