erupt

erupt or intensify suddenly

“Unrest erupted in the country”

force out or release suddenly and often violently something pent up

“erupt in anger”

break out

“The tooth erupted and had to be extracted”

start to burn or burst into flames

start abruptly

become raw or open

become active and spew forth lava and rocks

“Vesuvius erupts once in a while”

appear on the skin

“A rash erupted on her arms after she had touched the exotic plant”