Trichology is the dermatology branch dedicated to the study of diseases involving hair. It has its own techniques, like trichoscopy (augmenting exam of the hair and hair scalp), the trichrogram and the phototrichogram (they allow the evaluation of the hair cycle, thickness and growth) and other techniques normally used in dermatology like cutaneous biopsy.

It is impossible to understand trichology without first understanding dermatology. The existence of dermatologists who are dedicated to trichology is an added value and security for patients, since some of these diseases are not usual and the capacity to treat a patient well is determined by experience.

As in other medical areas, it is fundamental to reach a precise diagnosis in order to have an appropriate medical treatment. In 99% of the cases, a diagnosis is reached without the need to use invasive techniques (biopsy). Also, surgical technique – namely hair transplant – has depeloped a lot in the last years and allows the complementation of medical treatment.

Dr. Rui Oliveira Soares



General Dermatology, Trichology, dermatological Surgery, Oncology

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Dr. Miguel Peres Correia



Cosmetic dermatology, cutaneous Oncology, Trichology, dermatological Surgery

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Hair loss
Types of hair loss
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Live 4 More frequent questions during hair appointments
Live Myths about hair
Live Alopecia and hair transplant

Dandruff and flaking may be caused by endogenous conditions, usually inherited – dandruff (dry pitiriasis of the hair scalp), seborrheic dermatitis, psoriasis, líquen planopilaris, atopic eczema – or by external agression – irritating or allergic contact eczema. They are often combined with an itching or burning feeling which are the complaints that usually lead to the doctor appointment.

It is very rare for a skin condition to be caused by food. Some patients see a worsening in an existing condition on the hair scalp (psoriasis, seborrheic dermatitis, eczema) with alchool or spices and rarely with a specific food.

In most patients, stress causes the worsening of a chronic dermatological condition they already have (psoriasis, seborrheic dermatitis, eczema) but this is already very common on dermatosis in any area of the tegument (it is thought that neural- endocrine mediators alter the level of cytokines, causing inflammation).

Yes. Medicine can also cause alterations: redness, flaking, itching, etc. It can happen by two ways: Topic application of the medicine – for example, it may happen after using minoxidil locally (medicine for baldness) and in this case it is a consequence of the irritating action of the propilenoglicol and not an allergy to minoxidil; Systemic effect when you take a medicine to lower the uric acid, to control epilepsia or to control an infection (antibiotics). In these cases, there are usually other areas involved besides the hair scalp and it is important to have an early diagnosis and immediately stop taking the medicine. In some seleted cases it may be necessary to prescribe corticoids.

Yes. The usage of cosmetic can also restrict this type of expression, with a simple irritation or allergy. Allergy is an individual phenomena and it is usually detached from the quality of the used product. The most frequent cause is the application of hair dyes and the most frequent substance is parafenilenodiamina (PPD).

Seborrheic dermatitis and dandruff (different scales of the same phenomena) are differentiated from an allergic reaction by the clinical history (age, absence of a causing sensitizing), by the distribution (peripheral areas of the hair scalp and other affected areas), appearance of the scale, yellowish and greasy, and woody vessels detected in dermatoscopy (augmented vision).
In an allergic dermatitis it is important to evict the causing agent. In seborrheic dermatitis we can control it by using shampoos containing imidazolic by-products and ciclopirox olamina, solution or foam with corticoids, etc.

– Dandruff and seborrheic dermatitis – Thinking that it is curable and not having a regular maintenance.
– Psoriasis – Thinking that it is always treated the same way.
– Allergic reaction to the use of a cosmetic – Not stopping the application immediately, Not going to
see the doctor.

It is important to say that dandruff and seborrheic dermatitis are different levels of the same problem, the second being the most annoying because the scale adheres to the hair scalp. The predisposition is genetic and it affects mainly newborns, young adults and the elderly.

Dandruff (dry pitiriasis of the hair scalp) – We usually get a good control of dandruff with basic shampoos for flaking of the hair scalp, which contain ciclopirox olamina or imidazolic by-products.
From the supermarket (HS, Linic, etc) or from the pharmacy –Trikare K, Nodé DS, Trikare Z, Trikare Z, Kelual DS, KPL, etc.

Seborrheic Dermatitis – It usually requires, besides the above-mentioned shampoos, solutions or emulsions with queratolitics (they dissolve the adherent scale), corticoids (they control the inflammation) or imidazolic by-products (they control malassezia and fungi which, when excessive, can aggravate the seborrheic dermatitis). These topic medications must be prescribed by the family doctor or by the dermatologist. Oral medication with antifungals is rarely needed.

Psoriasis – It is also genetic and can affect people of any age. Light forms can be controlled with shampoo with tar by-products – tarmed, edoltar, etc. – or even with shampoos that control seborrheic dermatitis. Local treatment of the adherent scale is preferably done with queratolitics, which are often made with corticoids (psodermil, diprosalic,etc) and treatment of the inflammation with vitamine D by-products associated to corticoids (daivobet). In severe cases we use medicine acting systemically (metotrexato, acitretina, ciclosporina and modifiers of the inflammatory response, so called “biologic”.

Light forms can be controlled by the family doctor, the most severe by the dermatologist. Líquen planopilaris – With this disease, an early diagnosis by the dermatologist is fundamental, since its progress leads to the permanent loss of follicles (scar alopecia). It is treated topically (corticoids, tracolimus, etc.) or systemically (finasterida, dutasterida, tetracyclines, anti-malarials, corticoids, ciclosporina, etc.) in accordance with the degree of activity of the disease.

Atopic Eczema – It is preferably controlled with corticoids given topicaly although the severity of the disease may imply systemic medication with corticoids or other medicine.

Irritating or allergic by contact Eczema – The treatment consists of the eviction of what caused it and, in the acute form, topic or systemic corticoids, depending on the severity.

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