Alopecia
Hair loss is a very common reason for consultation in dermatology. However, not all types of "hair loss" are the same, and an accurate diagnosis is essential in order to establish an appropriate and effective treatment.
Causes
Alopecia can be caused by numerous factors. When it is genetic, it is referred to as androgenetic alopecia, and it may be due to hereditary as well as hormonal factors. It usually begins early, between the ages of 20 and 30. The hair becomes thinner and scarcer, hair density decreases considerably, and hair loss mainly affects the top of the scalp.
An excess of androgens can also cause alopecia. Diffuse universal alopecia may be due to various causes but is often related to an excess of male hormones. It presents differently depending on whether it affects men or women.
- In men, it follows the Hamilton pattern, initially affecting the frontotemporal area and the crown.
- In women, it follows the Ludwig pattern, with progressive thinning of the upper scalp while preserving the frontal hairline.
Work-related or emotional stress directly affects hair health. It can trigger telogen effluvium, which involves a temporary interruption of the normal hair growth cycle. During this time, hair does not regenerate as usual, resulting in less dense areas.
An unbalanced or inadequate diet—such as poorly planned fad diets—can also lead to hair loss. Iron or zinc deficiency are among the most common causes.
Immune system alterations and cellular inflammation are also behind many types of alopecia.
Symptoms
Although the main complaint is usually hair loss, shedding is not always the only issue. Other symptoms may include scalp itching, scaling, reduced hair density, and thinning of the hair shaft, either diffusely or in localized areas. Identifying which of these signs predominates can help guide the diagnosis.
There are two major groups of alopecia (the medical term used for these hair disorders):
- Scarring alopecias, which cause permanent hair loss.
- Non-scarring alopecias, which do not permanently destroy the hair follicle.
This initial classification is not always straightforward, making the role of a dermatologist specialized in trichology essential.
Not all hair problems originate in the hair itself. The scalp skin may also suffer from diseases or dermatoses that affect the hair shafts. In addition, hair shafts can be directly damaged by external aggressions.
Understanding each condition within these groups—scarring alopecias, non-scarring alopecias, scalp disorders, and hair shaft abnormalities—is crucial. A correct diagnosis is the only way to implement an appropriate, individualized, and effective treatment.
Diagnosis
The starting point for an accurate diagnosis of alopecia should always be consultation with a dermatologist specialized in trichology.
In addition to a thorough medical history and trichological examination, trichoscopy is necessary. Digital trichoscopy is currently the most valuable diagnostic tool. Besides refining the diagnosis, it facilitates patient follow-up.
In androgenetic alopecia, it provides data such as hair shaft count per square centimeter and average diameter, objectively showing the patient’s baseline condition and improvement with treatment.
In scarring alopecias, it allows more precise quantification of inflammation and disease activity in each area of the scalp. In some cases, a biopsy may also be necessary to establish a definitive diagnosis.
Treatment
In recent years, new therapies have been developed for hair loss, especially for androgenetic alopecia, and some existing treatments have been rediscovered with new routes of administration.
Hair mesotherapy with dutasteride delivers the medication directly to the hair follicles. Additionally, the microinjection stimulus itself may promote hair growth. It is a well-tolerated and highly effective therapy that can be combined with conventional treatments and platelet-rich plasma (PRP), which adds growth factors to the hair follicle.
Oral minoxidil has also represented a major advance in the treatment of androgenetic alopecia. It avoids the need for daily topical application—which can be inconvenient—and may offer greater effectiveness when administered orally. The dose must be individually adjusted by the dermatologist and modified according to the course of the disease.
Not all patients respond to topical minoxidil because its effectiveness depends on the presence of a specific enzyme in the scalp that processes the medication. Not all patients have sufficient levels of this enzyme locally. However, this enzyme is present in other internal organs, meaning that oral minoxidil will always be effective—even in patients for whom topical minoxidil has not worked.