rash 2 
(răsh)
(răsh)n.
1. A visible lesion or group of lesions on the skin, caused by any of numerous factors including infectious agents, drugs, and allergies.
2. An outbreak of many instances within a brief period: a rash of burglaries.
[Possibly from obsolete French rache, a sore, from Old French rasche, scurf, from raschier, to scrape, scratch, from Vulgar Latin *rāsicāre, from Latin rāsus, past participle of rādere; see rēd- in the Appendix of Indo-European roots.]