Medical Terms for Skin Darkening Concerns
Hyperpigmentation is the medical term for skin darkening concerns, which encompasses various conditions including melasma, post-inflammatory hyperpigmentation, solar lentigines, and ephelides (freckles). 1, 2
Types of Hyperpigmentation
Melasma: A common facial hyperpigmentation disorder characterized by symmetrical brown patches, predominantly affecting women and darker skin types. It's primarily attributed to ultraviolet exposure and hormonal influences. 3
Post-inflammatory hyperpigmentation (PIH): Darkening that occurs following skin inflammation or injury (e.g., after acne, eczema, or other skin conditions). 2, 4
Solar lentigines: Age spots or sun spots caused by cumulative sun exposure. 5
Ephelides: Commonly known as freckles. 5
Café au lait macules: Light brown patches that may be present at birth or develop in early childhood. 5
Exogenous ochronosis: A blue-black darkening of the skin that can occur as a complication of hydroquinone treatment, particularly in Black individuals but also in Caucasians and Hispanics. 6
Classification Based on Pathogenesis
Hyperpigmentation can be classified by its underlying mechanism:
Reactive vs. Non-reactive: Whether the pigmentation is a response to an injury or stimulus. 2
Epidermal vs. Dermal: Based on the depth of pigment deposition in the skin layers. 2, 1
- Epidermal: More responsive to topical treatments
- Dermal: More challenging to treat with topicals
Increased melanin vs. Increased cell number: Whether the darkening is due to more pigment or more pigment-producing cells. 2
Evaluation Methods
Melasma Area and Severity Index (MASI) and Modified Melasma Area and Severity Index (m-MASI): Validated scales used to measure the extent of facial hyperpigmentation and assess treatment response. 3, 1
Standardized photography: Recommended for tracking treatment progress at 4-6 week intervals. 1
Fitzpatrick skin typing: Important for determining treatment approach and risk of complications. 1
Common Pitfalls in Diagnosis
- Failing to distinguish between epidermal and dermal pigmentation, which affects treatment selection
- Not identifying underlying causes (hormonal, inflammatory, medication-induced)
- Confusing hyperpigmentation with other conditions that cause skin darkening
- Overlooking exogenous ochronosis as a potential complication of treatment 6
Understanding the specific type of hyperpigmentation is crucial for selecting appropriate treatment strategies and setting realistic expectations for patients regarding treatment outcomes.