Hydroquinone 4% is used to treat which skin condition?

Hydroquinone 4% is specifically used to treat hyperpigmentation, a condition characterized by darkened patches of skin caused by an excess of melanin. This can occur due to various factors, including sun exposure, hormonal changes, or post-inflammatory responses to skin injuries. Hydroquinone acts as a skin-lightening agent, inhibiting the enzyme tyrosinase, which plays a crucial role in melanin production. By reducing melanin synthesis, it effectively lightens the darkened areas of the skin, making it a common and effective treatment for conditions like melasma, age spots, and other forms of hyperpigmentation.

Other skin conditions listed, such as acne, eczema, and psoriasis, require different types of treatments. While acne often involves the use of topical retinoids or salicylic acid, eczema is typically addressed with moisturizers and corticosteroids, and psoriasis is treated with topical or systemic therapies that reduce inflammation and skin cell turnover. Thus, hydroquinone's mechanism of action and purpose are specifically aligned with treating hyperpigmentation.