Introduction
The white spots on the skin are an obvious symptom of local hypopigmentation, a condition in which the melanocytes are unable to produce adequate amounts of melanin, the pigment responsible for coloring the skin.
In this article we will examine in depth some situations in which white cutaneous spots are the protagonists: vitiligo, the most known and widespread dermatosis, Pityriasi Versicolor, cutaneous disorder of fungal nature and other probably less known skin disorders, but no less common for this.
Vitiligo
Features
The white spots represent the typical signs of vitiligo (also called leucoderma): it is a disorder of the skin, generally hereditary, which manifests itself above all in young people before the age of twenty. It is not a contagious disease: the damage is only of an aesthetic nature, even if the skin affected by the phenomenon could be more sensitive to light.
The white spots are the consequence of an alteration in the color of the skin (local hypopigmentation), caused by the lack of production of melanin (a pigment that defines the color of the skin) by melanocytes, which, while remaining alive, stop synthesizing melanin.
White spots can be spread throughout the body; preferentially, vitiligo occurs in the nails and in the areas of the body near openings (eyes, anus, genitals), but can also occur on the hands, face and neck.
As mentioned, white spots cannot be protected from tanning; in fact, due to the shortage of melanin produced, these areas are more prone to sunburn and erythema. The treatment of vitiligo, however, provides the outpatient administration of ultraviolet rays at specific wavelengths, sometimes associated with the application of photosensitizing substances; this practice, of medical competence, has precisely the purpose of reactivating the melanocyte function.
In vitiligo, the spots are white, asymmetrical, with slightly darker and outlined contours.
More than a physical problem, vitiligo is considered a psychological disorder: individuals suffering from this dermatosis may feel somehow rejected by others considered "normal" because of the unsightly problem.
Causes
As far as the etiology is concerned, therefore the search for the triggering causes, it can be said that there are no precise factors: the origin of vitiligo is, therefore, doubtful, although a genetic predisposition tends to register. Stress and decreased immune defenses may also affect vitiligo potentiation; similarly, dysfunctions of the thyroid can cause scattered white spots on the skin. On the other hand, vitiligo can be a wake-up call for other disorders, of greater magnitude, involving dysfunctions and hyperactivity of the immune system, such as type I diabetes and Addison's disease; not surprisingly, it is often associated with alopecia areata.
Treatment
The treatment of vitiligo involves the cutaneous application of photosensitizing substances associated with irradiation with UV rays at certain wavelengths. This particular type of treatment is called "PUVA therapy" (for more information: Vitiligo).
Pityriasis Versicolor
Features
The white spots scattered on the skin can hide more serious problems than a "simple" vitiligo: sometimes, these whitish patches can be the cause of a fungal skin infection, Pityriasi Versicolor .
Causes
Among the fungal microorganisms that dwell on the skin stands the Pityrosporum Orbicolare : it is a saprophyte, that is a microorganism normally present in the skin; more specifically, it lives near the hair follicle and feeds on the secretion of the sebaceous glands. In normal conditions it does not create damage.
When factors such as sebaceous hypersecretion, intense sweating, genetic predisposition and decreased immune defenses (a consequence of pharmacological treatments, for example) intervene, the micro-organism develops in the pathogenic Pityrosporum Ovale : being more aggressive, it infects the skin making it spotted with patches of various colors, which progress from a white shade to red. For this reason, the skin infection is called Pityriasi Versicolor, characterized by roundish spots whose diameter can even touch two centimeters.
Treatment
This infection is not always recognized: the dermatologist has the task of identifying it promptly and will advise the patient on a treatment with antifungal drugs.
The disorder is not contagious and does not entail serious health consequences, but it can create psychological problems in the subject (such as vitiligo), which may have the perception, even if it is unfounded, of being "sick": white spots may persist even after having eradicate the infection and this makes the skin decidedly unsightly.
Pityriasis Alba
Features
Pityriasis alba is a disorder that affects skin pigmentation and manifests itself in the form of white spots on the skin.
The stains that characterize this disorder are round, or oval, but the margins are not well defined, but rather blurred. The central area of these white spots is usually flaky.
Pityriasis alba mainly affects children and adolescents between 3 and 16 years of age, with a higher incidence in males than in females.
Causes
It is a disorder that is not exactly the cause, although - often and willingly - it occurs in patients with particularly dry skin and / or affected by other skin diseases, such as atopic dermatitis or psoriasis.
Treatment
It is not a contagious disease and generally does not require the use of particular therapies, since it tends to be self-limiting.
It can be useful to keep the skin well hydrated and protected from UV rays by using appropriate sunscreens.
In some cases, in order to limit the appearance of white spots on the skin, the doctor may consider it necessary to use mild corticosteroids, but only under his supervision and only for short periods of time.
Idiopathic guttate hypomelanosis
Features
Idiopathic guttate hypomelanosis is another skin pigmentation disorder that causes the appearance of small white spots on the skin.
It is not contagious and occurs mainly in people of a certain age.
The white spots that characterize this disorder are generally small (diameter less than 5 mm) and with well-defined contours. They occur with greater incidence on the forearms and legs, but can also affect the face or other parts of the body.
Causes
It is believed that the cause of idiopathic guttate hypomelanosis is to be found in several factors, such as the processes of skin aging and microtrauma suffered by the skin during the patient's life. More precisely, it is customary to assume that the white spots on the skin caused by this disorder are attributable to the damage suffered by the melanocytes following uncontrolled sun exposure. In fact, these spots generally appear on the areas of the body most exposed to the sun.
Treatment
Unfortunately, there are no specific and conclusive therapies for the treatment of idiopathic guttate hypomelanosis. Therefore, prevention is the best weapon currently available against this disorder.
The formation of white spots on the skin can be prevented by taking care to use adequate sunscreens whenever you are exposed to the sun, taking care to avoid the hottest hours of the day.
Other causes
In addition to those described so far, white spots on the skin can also be caused by numerous other causes of various origins and nature, such as, for example, nutritional deficiencies or the use of certain types of drugs.
In other cases, however, white spots on the skin may represent the side effect or complication of some dermo-aesthetic treatments (such as can occur, for example, following anti-wrinkle treatments with laser technologies).
Furthermore, the white spots on the skin can represent the result of trauma ( post-traumatic hypopigmentation ) or of some inflammatory pathologies ( post-inflammatory hypopigmentation ), such as, for example, bullous dermatitis, eczema or skin infections.
