Detailed answer

Hot showers and steam can stimulate melanin production in the skin, which can worsen melasma. The heat can also cause skin inflammation and dilation of blood vessels, leading to an increase in pigmentation. Additionally, hot water can strip the skin of its natural oils, causing dryness and sensitivity, further aggravating melasma. It is advisable to use lukewarm water while showering and avoid excessive exposure to steam or heat to help prevent melasma flare-ups.