This seems like what Malays call it, “panau”. I quote from Google; “Tinea versicolor is a fungal infection of the skin. It's also called pityriasis versicolor and is caused by a type of yeast that naturally lives on your skin. When the yeast grows out of control, the skin disease, which appears as a rash, is the result. The infection can happen for any of the following reasons: - You have oily skin - You live in a hot climate - You sweat a lot - Hormonal changes - You have a weakened immune system Because the yeast grows naturally on your skin, tinea versicolor is not contagious. The condition can affect people of any skin color. It's more likely to affect teens and young adults. Signs and Symptoms of Tinea Versicolor: - Acidic bleach from the growing yeast causes areas of skin to be a different color than the skin around them. These can be individual spots or patches. Specific signs and symptoms of the infection include: - Patches that may be white, pink, red, or brown and can be lighter or darker than the skin around them. - Spots that do not tan the way the rest of your skin does. - Spots that may occur anywhere on your body but are most commonly seen on your neck, chest, back, and arms. - The spots may disappear during cool weather and get worse during warm and humid weather. They may be dry and scaly and may itch or hurt, although this is not common.”