Skin pigmentation refers to the natural colouring of the skin caused by melanin production. Hyperpigmentation occurs when melanin is overproduced in certain areas, leading to dark patches or uneven tone.
Understanding the underlying cause is essential for effective treatment.
How Melanin Affects Skin Colour
Melanin is produced by melanocytes and acts as a natural defence against ultraviolet radiation. When skin is exposed to UV rays, melanin production increases to protect deeper layers.
Two primary forms of melanin determine skin tone:
- Eumelanin: Brown to black pigment
- Pheomelanin: Red to yellow pigment
Hyperpigmentation develops when melanocytes become overactive in specific areas.
Main Causes of Hyperpigmentation
1. Sun Exposure
Ultraviolet radiation is the leading cause of pigmentation issues.
Repeated sun exposure leads to:
- Age spots (solar lentigines)
- Uneven skin tone
- Worsening of existing pigmentation
Effects accumulate over time, making consistent sunscreen use essential.
2. Hormonal Changes (Melasma)
Hormonal fluctuations during pregnancy, oral contraceptive use, or menopause can stimulate melanin production.
Melasma typically appears as symmetrical brown patches on:
- Cheeks
- Forehead
- Upper lip
- Chin
Sun exposure intensifies this condition.
3. Post-Inflammatory Hyperpigmentation (PIH)
PIH develops after skin injury or inflammation, including:
- Acne
- Cuts or burns
- Waxing
- Aggressive treatments
It appears as dark marks that remain after the original inflammation heals.
4. Ageing
As skin ages:
- Cell turnover slows
- Melanin distribution becomes uneven
- Dark spots become more visible
Sun damage accumulated over the years often becomes noticeable later in life.
5. Medications and Chemical Reactions
Certain medications can increase photosensitivity, including:
- Some antibiotics
- Anti-seizure medications
- Hormonal treatments
Phototoxic reactions can trigger pigmentation when exposed to sunlight.
6. Genetic Factors
Genetic influence:
- Melanocyte activity
- Response to sun exposure
- Likelihood of developing melasma or freckles
Individuals with Fitzpatrick skin types IV–VI are more prone to post-inflammatory hyperpigmentation.
How Long Does Treatment Take?
- Topical treatments: 8–12 weeks
- Clinical treatments: Visible results after multiple sessions
- Deeper pigmentation: Requires longer-term management
Consistency determines success.
Conclusion
Hyperpigmentation results from increased melanin production triggered by sun exposure, hormonal changes, inflammation, ageing, medications, or genetic factors. Accurate diagnosis is essential for selecting the appropriate treatment approach.
Early intervention improves outcomes and reduces recurrence risk.
