If you talk about a rash of events or things, you mean a large number of unpleasant events or undesirable things, which have happened or appeared within a short period of time.
2. a series of unexpected and unpleasant occurrences;
"a rash of bank robberies""a blizzard of lawsuits"
Adjective
1. imprudently incurring risk;
"do something rash that he will forever repent"- George Meredith
2. marked by unthinking boldness; with defiant disregard for danger or consequences;
"foolhardy enough to try to seize the gun from the hijacker""became the fiercest and most reckless of partisans"-Macaulay"a reckless driver""a rash attempt to climb the World Trade Center"