From the Guidelines
Hyperpigmentation is primarily caused by ultraviolet (UV) exposure and hormonal influences, as evident in conditions like melasma, which is more prevalent in females and darker skin types. According to the study published in 2025 1, melasma is an acquired pigmentary skin condition that occurs most commonly on the face and can be esthetically displeasing to the patient. The causes of hyperpigmentation can be broken down into several key factors, including:
- Sun exposure, which triggers melanin production as a protective response
- Hormonal changes, particularly during pregnancy (melasma) or from birth control pills
- Post-inflammatory reactions following skin injuries, acne, eczema, or psoriasis
- Certain medications like antibiotics (tetracyclines), antimalarials, chemotherapy drugs, and antiseizure medications
- Genetic factors that predispose some individuals to conditions like freckles or lentigines
- Medical conditions such as Addison's disease and hemochromatosis
- Age-related changes, with liver spots developing over time from cumulative sun damage
The study 1 highlights the importance of evaluating the efficacy and safety of treatments for melasma, including topical therapies like hydroquinone, tretinoin, corticosteroids, and tranexamic acid. The Melasma Area and Severity Index (MASI) and the Modified Melasma Area and Severity Index (m-MASI) are validated scales used to measure the extent of facial hyperpigmentation, allowing for the assessment of response to treatment. To prevent hyperpigmentation, it is essential to use broad-spectrum sunscreen daily (SPF 30+), wear protective clothing, avoid peak sun hours, and treat underlying skin conditions promptly. For existing hyperpigmentation, topical treatments containing hydroquinone, retinoids, vitamin C, kojic acid, or azelaic acid may help, while more severe cases might benefit from procedures like chemical peels, microdermabrasion, or laser therapy under dermatological supervision.
From the FDA Drug Label
Skin: ... hyperpigmentation of nails, pruritus, ... Pigmentation of the skin and mucous membranes has been reported. Temporary hyper- or hypopigmentation has been reported with repeated application of tretinoin. The causes of hyperpigmentation mentioned in the drug labels are:
- Minocycline (PO): hyperpigmentation of nails, pigmentation of the skin and mucous membranes 2
- Tretinoin (TOP): temporary hyperpigmentation with repeated application 3
From the Research
Causes of Hyperpigmentation
- Hyperpigmentation can be caused by various factors, including light exposure, hormonal influences, and family history 4
- Melasma, a common form of hyperpigmentation, is associated with a high psychological burden of disease and can be exacerbated by sun exposure 5
- Postinflammatory hyperpigmentation (PIH) is another common form of hyperpigmentation, often occurring after inflammation or injury to the skin 5
Types of Hyperpigmentation
- Epidermal hyperpigmentation: characterized by increased pigmentation in the epidermis, often caused by sun exposure or hormonal changes 6
- Dermal hyperpigmentation: characterized by increased pigmentation in the dermis, often caused by inflammation or injury to the skin 6
Risk Factors
- Skin type: hyperpigmentation is more common in individuals with Fitzpatrick skin types III to VI 6
- Hormonal influences: hormonal changes, such as those experienced during pregnancy, can contribute to hyperpigmentation 4
- Family history: individuals with a family history of hyperpigmentation are more likely to experience it themselves 4
Diagnosis and Treatment
- Diagnosis of hyperpigmentation often involves a combination of physical examination, Woods light examination, and histological analysis 6
- Treatment options for hyperpigmentation include topical agents, such as hydroquinone and tretinoin, as well as oral agents, such as tranexamic acid 7, 8
- Combination therapy, such as the use of oral tranexamic acid and topical hydroquinone, may be more effective than monotherapy in treating melasma 8