Why does the skin darken unevenly?
The pigment melanin is responsible for skin color, which is produced by special cells - melanocytes, located in the lowest layer of the epidermis. Melanin acts as a built-in protective shield: it absorbs ultraviolet light and protects the cell nuclei from damage. When the sun hits the skin, melanocytes receive a signal and increase the production of pigment - this is how a tan appears. The problem begins when this process becomes uneven: some cells respond to the stimulus excessively, others respond normally, and instead of an even tone, spots are obtained. Such a malfunction can be triggered by ultraviolet radiation, hormones, inflammation, trauma, certain medications, and skin contact with certain plants and cosmetic components.
It is also important at what depth the pigment lies. If melanin is in the epidermis, the spot appears light brown with clear boundaries, and it is relatively easy to lighten it. If the pigment has sunk into the dermis, the shade becomes grayish-bluish or brown, the boundaries are blurred, and any treatment is slower and worse. This is determined not only by the type of spot, but also by its age: the longer hyperpigmentation exists, the higher the likelihood that part of the pigment has already moved deeper. Hence the practical conclusion - fresh spots can be corrected much better than those that are many years old.
- Solar lentigo - flat brown spots with clear boundaries on the face, hands, shoulders and décolleté; the result of many years of exposure
- Melasma - symmetrical spots with blurred edges on the forehead, cheekbones, and above the upper lip; related to hormones and sun
- Post-inflammatory hyperpigmentation - a dark mark at the site of a former pimple, burn, scratch or eczema
- Freckles are a genetic feature of fair skin; they darken in summer and fade in winter.
- Drug and photosensitizing pigmentation - against the background of certain drugs that increase skin sensitivity to the sun
- Pigmentation after contact with plant sap and subsequent exposure to the sun - clear stripes and oddly shaped prints
Melasma: Why is it special?
Melasma is isolated separately because it is more complex than other pigmentation and behaves differently. These are symmetrical spots with unclear boundaries, most often on the forehead, cheekbones, cheeks and above the upper lip. They predominantly affect women, much more often those with dark skin, and a significant proportion of cases first appear during pregnancy. Hence the old name “pregnancy mask”. The second most common trigger is starting to take hormonal contraceptives or hormone replacement therapy.
- Hormonal background - pregnancy, hormonal contraceptives, replacement therapy, less often thyroid disorders
- The sun is an obligatory participant: without ultraviolet light, melasma does not appear and is not supported
- Heat itself also provokes spots: a hot kitchen, sauna, prolonged exposure to heat intensifies the manifestations even without direct sun
- Heredity - melasma often occurs in several women in the same family
- Visible light, including screens and some lamps, can support pigmentation in dark skin.
- Some cosmetic components and aggressive procedures act as an additional irritant
Melasma during pregnancy often fades on its own within several months after childbirth and the end of breastfeeding, so aggressive treatment is usually not started during this period - it is limited to sun protection and safe external remedies. If spots remain, treatment begins later, when hormonal levels have stabilized. In connection with hormonal contraceptives, the issue of changing them is discussed with the gynecologist: without this, pigmentation will return after each course of lightening, and the patient himself will decide that “nothing helps.”
How to distinguish a stain from a dangerous formation
The main task of the initial examination is not to select a lightening agent, but to make sure that we are dealing with benign hyperpigmentation. A seemingly harmless spot sometimes turns out to be a completely different process, and no cosmetic procedures are performed before diagnosis.
- Осмотр и сбор анамнеза: когда появилось, как менялось, что предшествовало — беременность, роды, начало приёма препаратов, отпуск на море, воспаление на этом месте.
- Дерматоскопия — осмотр под многократным увеличением с поляризованным светом. Позволяет увидеть структуру пигмента и отличить лентиго, себорейный кератоз, невус и подозрительное образование.
- Осмотр под лампой Вуда — помогает понять глубину залегания пигмента: поверхностная пигментация под этим светом становится контрастнее, глубокая почти не меняется. От этого зависит прогноз и выбор метода.
- Фотодокументирование — обязательный этап при мелазме, потому что изменения идут медленно и оценить их по памяти невозможно.
- Анализы по показаниям: гормоны щитовидной железы, ферритин, при подозрении на системные причины — расширенное обследование.
- Биопсия — при любом обоснованном подозрении на злокачественное образование; выполняется до, а не после косметических манипуляций.
Treatment: a procedure that works
Lightening pigmentation is always a combination of three components: eliminating the cause, sun protection and lightening therapy itself. Skipping any of them devalues the rest, and most often it is the protection that is missed, and then they conclude that the treatment is ineffective.
- Защита от солнца — фундамент. Средство широкого спектра с высоким фактором, ежедневно, с повторным нанесением. При мелазме предпочтительны средства с минеральными фильтрами и тонирующим пигментом, которые дополнительно перекрывают видимый свет.
- Устранение провоцирующего фактора: пересмотр гормональной контрацепции вместе с гинекологом, отмена фотосенсибилизирующих средств, лечение воспалительных заболеваний кожи.
- Наружная терапия — азелаиновая кислота, ниацинамид, ретиноиды, производные витамина C, средства, тормозящие выработку меланина. Курс длительный, первые изменения оценивают через 8-12 недель.
- Химические пилинги — курсом, с постепенным повышением концентрации, в период низкой солнечной активности.
- Аппаратные методы — лазерные и световые технологии. При солнечном лентиго они дают быстрый и надёжный результат, при мелазме применяются осторожно и по строгим показаниям.
- Поддерживающая терапия — самый недооценённый этап; без него результат теряется в течение сезона.
It’s worth mentioning separately about laser for melasma. It seems logical to “just burn” the spot, and for solar lentigo this actually works. But with melasma, melanocytes are in a state of increased excitability, and aggressive thermal exposure can provoke the opposite effect - the pigmentation returns darker and spreads wider than it was. Therefore, gentle regimes are used here, always after preparing the skin with external means, and never as the first and only step.
Dangerous home lightening methods
Folk recipes for removing stains have been passed down for decades, and almost all of them are based on the same principle - apply an acid or oxidizing agent to the skin without controlling the concentration and time. The result is predictable: damage to the skin barrier, inflammation, and then even more pronounced pigmentation at the burn site. The skin darkens in response to damage, so these methods work exactly the opposite of what you might expect.
- Lemon juice is a concentrated acid with an unpredictable pH; upon contact with skin followed by exposure to the sun, it causes a phototoxic reaction with blisters and persistent, oddly shaped brown spots
- Vinegar is a chemical burn of varying depth, especially on the thin skin around the eyes.
- Soda - mechanical damage and a sharp shift in skin acidity, destroying the protective barrier
- Hydrogen peroxide - discolors the surface layer for several hours, and then provokes inflammation and darkening
- Celandine - causes a chemical burn with subsequent scarring; especially dangerous when trying to remove a mole
- Any independent reduction of a mole by cauterization or a folk remedy is the destruction of the formation without histological examination, that is, the loss of information about what it was
The phototoxic reaction to plant juices deserves special mention because it is rarely attributed to a cause. The juice of citrus fruits, figs, hogweed and a number of other plants contains substances that are harmless in themselves, but become aggressive under the influence of ultraviolet radiation. The classic picture is redness, and then clear brown streaks, fingerprints or streaks on the skin that appear a day or two after making lemonade in the sun or relaxing in nature. These spots last for months, and it takes much longer to treat them than the pigmentation for which everything was started.
