There are 39 conditions associated with excessive sweating and skin rash. The links below will provide you with more detailed information on these medical conditions from the WebMD Symptom Checker and help provide a better understanding of causes and treatment of these related conditions.
Sunburn is often associated with a rash that begins as a small, pink patch on the skin or a mole-like spot than then start spreading out. The rash appear within 12 to 24 hours after exposure to UV rays and can be particularly worse if you are under certain medications such as Doxycycline.
Skin layers and melanin. Sunburns are caused by exposure to too much ultraviolet (UV) light. UV radiation is a wavelength of sunlight in a range too short for the human eye to see. Ultraviolet A (UVA) and ultraviolet B (UVB) are the two types of solar radiation most responsible for sunburn. Sunlamps and tanning beds also produce UV light and can cause sunburn. Melanin is the dark pigment in the outer layer of skin (epidermis) that gives your skin its normal color.