What is skin depigmentation
Cutaneous depigmentation, or hypopigmentation, refers to the loss of normal skin pigmentation and is by definition not congenital. Depigmentation can occur without any obvious cause or be secondary to an inflammatory dermatosis in the healing phase.
Vitiligo essentially consists of an acquired loss of melanocytes with the appearance of achromic areas, sometimes associated with other autoimmune diseases.
This condition is quite common and usually affects certain areas of the skin such as the hands, face and areas around the orifices: it is characterized by the appearance of white spots on the skin, which can spread over time and affect also adjacent areas.
Sometimes the presence of spots on the skin can be due to a fungal infection, the so-called pityriasis versicolor, a common, non-contagious skin disease, due to the invasion of the most superficial layers of the epidermis (stratum corneum) by yeasts of the Malassezia species, saprophytic fungi from regions rich in sebaceous glands.
This mycosis, rare before puberty, prefers young adults with a recurrent tendency and a predominant location in the shoulders and thorax, which can extend to the abdomen, neck and arms.
The lesions are flat or slightly raised, first punctate then become lenticular and then tend to flow into irregular, geographic or polycyclic shapes with sharp borders. Compared to vitiligo, they are characterized by a finely wrinkled surface or more clearly covered with furfuraceous scales, sometimes detectable only by the characteristic “nail” sign.
- Lesions vary in color from white of the hypochromic variety to yellow-brown or milky coffee and buff color of the hyperchromic form.
- Hypochromia is reversible and more evident after photoexposure.
- The microorganism that triggers this type of infection, in fact, blocks the production of melanin, initially generating round white spots on the skin, especially on the back, back and neck.
Like vitiligo, this problem is neither contagious nor dangerous to health, but it can cause psychological discomfort, especially in the case of spots on the face. However, skin depigmentation can also be generalized and affect the whole body: classic examples are albinism and phenylketonuria.
Causes of skin depigmentation
Skin depigmentation can be caused by a number of local and systemic diseases. Pigment loss can be partial (for example, after a skin injury) or complete (for example, when you have vitiligo). Skin depigmentation can be temporary (as in pityriasis versicolor) or permanent (as in albinism).
Hypopigmentation or depigmentation of the skin affects certain areas of the skin, in which the melanocytes do not produce sufficient amounts of melanin.
The most common skin dyschromia caused by insufficient production of melanin is vitiligo (or leucoderma), the triggering factors of which have not yet been identified with certainty. In general, a genetic predisposition to vitiligo has been identified, and it is also believed that there are certain predisposing factors such as:
- excessive stress
- decrease in immune defenses
- thyroid dysfunctions