Presuming you are talking about acne...
Environmental, dietary, and hormonal factors are the main causes of "flare ups" in acne prone skin.
Smog and pollution deposit irritants into the skin, and while you are often able to wash these irritants away, sometimes, they become inflamed and cause pimples.
Greasy, fat heavy foods often contribute to poor skin. A simple dietary change is making sure you eat a lot of fibre, and get your Omega 3 fatty acids.
Hormones can also affect the production of oil in your skin- this is why Birth Control often assists in controlling acne.
Oily and fried food can cause flare up with the acne rosacea.
Cause a fire, no. However, if conditions are right, it can cause a fire to flare up.
Doe smoking cause lupus flare ups
Most unlikely to be the cause of flare up
Hemorrhoids can flare up due to factors such as straining during bowel movements, chronic constipation or diarrhea, sitting for long periods of time, obesity, pregnancy, and a low-fiber diet.
It is not unheard of that a condition like hives can coincide with a flare up in arthritic condition's,
taking this can actually cause a flare up before your levels are under control
A wheal and flare reaction is a type of response seen in a skin allergy test, such as a skin prick test. It involves the development of a raised, red lump (wheal) at the site where an allergen is introduced to the skin, along with surrounding redness and inflammation (flare). This reaction indicates an immune response to the allergen.
Solar flares themselves do not cause skin cancer directly. However, solar flare events can increase the ultraviolet radiation that reaches the Earth's surface, leading to a higher risk of skin damage and potential risk of skin cancer if adequate sun protection measures are not taken.
In the context of the allergic wheal and flare reaction, the flare is the redness one sees on the skin after an allergen has been injected. The wheal is the indurated (hard) bump.
The flare is easier because you don't need to keep yourself up in the air.
Rheumatoid arthritis flare up, eczema, goiter, and open skin lesions.