Chemical burns and Leukeran?

Hello, I was wondering if any of you are giving liquid leukeran to your kitties. Mine has been on it for about 1.5 months. Yesterday, as I was brushing away a mat from his chest, I noticed a very dark red/purplish lesion. The fur in the area just all clumped off and it was scabby and blistery. I took him to ER and they said it could be due to his prednisolone/leukeran combo that he's on, since they can both cause suppression of his immune system. That maybe he got a cut or something that turned into an infection. It was right in the area where the medication drips from him spitting or not swallowing it all. So I wonder if the chemicals in the leukeran can cause scalding or chemical burns to the skin. I'm taking him into his regular vet tomorrow, but I was curious to know if anyone out there has experienced this. 

Hmmm I'm not a vet but the emergency vet's explanation sounds logical to me.

Leukeran drug info gives no indication of any acid-related issues, so I doubt there's an issue of a chemical burn. There are many warnings there about side-effects related to the weakened immune system, many of them involving the skin barrier.

Welcome to TCS and please do let us know what your regular vet said and how the cat is doing!