Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. You may be developed allergy to steroid injection or it may be secondary rash to viral infection. Moisturex cream locally, use anti histamine like tablet Atarax twice a day for five days. If symptoms not improved please consult your physician he will check for platelet count, other parameters. Hope I have answered your query. Let me know if I can assist you further.