Hyperpigmentation: Types, Causes and How Each Is Treated

Hyperpigmentation is a broad term for areas of skin that appear darker than the surrounding tissue due to increased melanin concentration. It covers several distinct conditions that share a visible outcome but differ significantly in their cause, the depth at which the pigment sits, and how each responds to treatment. Applying the wrong treatment to the wrong type of pigmentation does not work and can, in some cases, make the condition worse.

This article explains the clinical distinctions between the most common types of hyperpigmentation, what determines whether a case is likely to respond well to treatment, and how each is approached at The London Road Clinic.

Why the type of pigmentation matters

Melanin is produced by melanocytes, specialised cells in the deepest layer of the epidermis. When melanocyte activity is increased by UV exposure, inflammation, hormonal stimulation or injury, excess melanin is deposited either within the epidermis or in the dermis, or in both. The depth of that pigment determines how visible it is, how it responds to light and how it responds to treatment.

Epidermal pigmentation sits close to the surface. It appears brown in daylight and responds more readily to energy-based treatments such as IPL and superficial chemical peels. Dermal pigmentation sits deeper and often appears grey-brown or slate-grey in daylight. It is harder to treat and responds more slowly.

Assessing depth is one of the most important steps in any pigmentation consultation. At The London Road Clinic, the Observ 520 skin analysis system uses different wavelength modes to reveal subsurface pigmentation, distinguishing epidermal from dermal deposits before a treatment plan is agreed.

The most common types

Solar lentigines (age spots, sun spots) are the result of cumulative UV exposure over years or decades. They appear as discrete, flat, well-defined brown spots, most commonly on the face, backs of hands, shoulders and decolletage. They are typically epidermal and respond well to IPL and superficial peels.

Post-inflammatory hyperpigmentation (PIH) follows skin injury or inflammation. Acne is the most common cause in aesthetic clinic patients. In people with Fitzpatrick skin types IV-VI, PIH tends to be deeper, more prominent and longer-lasting because the skin has a higher baseline melanocyte density and a more robust inflammatory response to injury.

Freckles (ephelides) are genetically determined and UV-triggered. They are characteristically epidermal and lighten significantly in winter. Treatment reduces them but does not prevent their return with continued UV exposure.

Melasma is the most complex and most resistant type. It presents as symmetrical brown or grey-brown patches, typically across the forehead, cheeks, upper lip and chin, and is driven by the combination of UV exposure and hormonal influence. The pigment in melasma is often mixed: partly epidermal, partly dermal. Melasma has a high recurrence rate because the hormonal trigger, if still present, continues to drive melanogenesis.

What determines treatment response

Depth. Epidermal pigment responds better to most aesthetic treatments than dermal pigment.

Skin tone (Fitzpatrick type). Treatments that deliver energy to the skin carry a higher risk of triggering post-inflammatory hyperpigmentation in darker skin tones. Treatment protocols for Fitzpatrick IV-VI skin require lower energy settings, more conservative peel strengths and a longer observation period between sessions.

Hormonal status. Active hormonal stimulation means that melasma will continue to be driven from within, regardless of what is done at the surface.

Sun protection compliance. Any treatment for pigmentation is substantially undermined without daily broad-spectrum SPF use.

How each type is approached at LRC

Solar lentigines. Lumecca IPL is the first-line choice for most patients with Fitzpatrick I-III skin. Chemical peels are a useful adjunct, particularly where multiple superficial concerns are present.

Post-inflammatory hyperpigmentation. For lighter skin tones with predominantly epidermal PIH, Lumecca IPL and chemical peels are effective. For deeper skin tones, a topical-first approach is often more appropriate. SkinPen microneedling combined with targeted serums can support PIH management across skin tones with lower PIH risk than IPL or ablative treatments.

Melasma. Epidermal melasma can be improved with IPL (with caution), superficial peels and rigorous topical treatment. Dermal or mixed melasma is much harder. Polynucleotides are sometimes included for their anti-inflammatory properties. The single most important intervention for melasma remains daily broad-spectrum SPF.

All pigmentation concerns. An Observ skin analysis at the start of a pigmentation treatment programme provides an accurate baseline and allows progress to be tracked objectively.

Frequently asked questions