Melasma

Melasma is a chronic acquired skin condition marked by irregular brown or gray-brown patches, usually on the face. It involves excess melanin production and often recurs after treatment.

Melanocyte: A skin cell that produces melanin and transfers it to neighboring cells. Melasma involves increased pigment production by melanocytes in affected skin.
Wood's lamp: A long-wave ultraviolet light used to examine skin and make some pigment patterns more visible. It can help assess pigment depth, though findings are less reliable in darker skin.
Post-inflammatory hyperpigmentation: Darkened skin that develops after inflammation or injury. Unlike melasma, it usually follows a specific inflammatory event or skin injury.
Relapse: The return or worsening of a condition after improvement or remission. Melasma commonly returns, especially with renewed sun exposure or hormonal triggers.
Melanin: A group of pigments that give color to skin, hair, and eyes and help absorb ultraviolet radiation. Excess melanin creates the characteristic dark patches.
Dermoscopy: A noninvasive method of examining skin with magnification and specialized illumination. It can reveal pigment patterns that support clinical assessment of melasma.
Solar lentigo: A sharply defined, persistent pigmented spot caused by cumulative sun exposure. Its discrete spots contrast with melasma's broader, often symmetrical patches.
Photoprotection: Measures that reduce exposure to harmful effects of sunlight. Long-term sun protection is central because light can reactivate pigmentation.
Ultraviolet radiation: Electromagnetic radiation with wavelengths shorter than visible light, including UVA and UVB. Sun exposure can stimulate pigment production and worsen melasma.
Hydroquinone: A topical skin-lightening agent that reduces melanin production. It is a common prescription treatment for melasma, often used in combination formulas.

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MelanogenesisRelated: Its excess pigmentation reflects increased melanin production and deposition in affected skin.