Is ‘dermal’ melasma a real thing?

Is ‘dermal’ melasma a real thing? #askdrnatalia The majority of my melasma patients have seen countless other healthcare professionals for treatment before coming to me. One thing I hear very often is that their previous treatments failed because they have ‘dermal’ melasma. At least that is what they have been told as the reason why the treatment did not work.

This is odd to me because there is no such thing as ‘dermal’ melasma – this is an archaic term based on biopsy studies of melasma skin without reference to controls (Sanchez et al JAAD 1981) and has already been shown to be incorrect. Kang et al (BJD 2002) did the first case-control study looking at the histology (what the skin looks like under a microscope) of melasma facial skin compared to normal skin next to the melasma skin in 56 Korean women (average age of 37).

The findings are super interesting: Both areas of skin showed evidence of chronic sun damage Melasma skin had more melanin (pigment) in the entire epidermis than the non-melasma skin, in which the melasma was mainly only in the bottom of the epidermis where it normally should be. Melasma skin has more melanocytes and melanin in the epidermis than non-melasma skin. There was no significant difference in the amount of melanin in the dermis of melasma vs non-melasma skin indicating that there is no ‘true’ dermal melasma type. Melasma is epidermal hyperpigmentation. The melasma melanocytes in the epidermis have abnormally super active melanin synthesis via an enzyme called tyrosinase. ‘Deactivating’ this enzyme is the key to clearing melasma.