Differential diagnosis and management of hyperpigmentation.

There is an increasing recognition of ethnic dermatology to reflect the rising skin of colour (SOC) population. Hyperpigmentary disorder is one of the commonest skin concerns in SOC but there have been limited training available in this field of dermatology. Variations in skin colour is genetically determined by the amount of melanin content, eumelanin:pheomelanin ratio and size of melanosomes but also influenced by extrinsic factors such as ultraviolet (UV) and hormones. Hyperpigmentation is a broad terminology describing increased pigmentation and making a correct diagnosis is an important first step in the successful management of hyperpigmentary disorder. A systematic approach based on its pathogenesis (e.g., reactive vs. non-reactive, increased melanin vs. increased number of cells or epidermal vs. dermal pigmentation) aided by a detailed history and clinical examination would be best way to diagnose a hyperpigmentary disorder. Based on its pathogenesis, management can be planned. For epidermal hyperpigmentation caused by increased melanin, topical skin lightening agents targeting inhibition of tyrosinase or melanosome transfer as well as increasing keratinocyte turnover can be used. Hydroquinone-containing cream is the gold standard treatment for epidermal hyperpigmentation. Alternative treatments include laser toning or chemical peels. However, increased dermal pigmentation is more challenging to target with topical treatments. If hyperpigmentation is due to the increased number of melanocytes or keratinocytes, high-fluence treatment with laser would be most appropriate