I wondered if anyone has any advice. My DS who is 10 has a large tanned coloured patch on the side of his chin that appears after UV exposure. It appears in spring and fades to barely noticeable over winter and started about 3 years ago. GP had no idea, but I'm going to ask for a dermatologist referral as it's very noticeable now. Not itchy, red or any change to the texture of the skin. It looks like melasma but from what I can read that is always symmetrical over the centre of people's faces, not one sided. Anyone have any experience or ideas of what it may be?