The 1st stage commences after an incubation period of about three times with a small pores and skin lesion at the location of entry. It could bring about the overlying pores and skin to stop working (ulcerate) but heals so swiftly that it may well pass unnoticed. GMC J.D. Power https://www.truckspares365.co.uk/hub/guide-to-shock-absorbers/