Hi there. From your description, history & clinical features associated, it is very possible to be either a 'viral' or 'rickettsial' infection or a hypersensitivity reaction / serum sickness kind of picture. The rash you describe is probably 'petechaie' & a local small vessel vasculature reaction pattern of the skin. the sore knee joints & slight nausea suggest a 'systemic' involvement. have you been travelling outdoors recently, been bitten by fleas/bugs, similar features in other friends/contacts/pets/familia are some of the questions you should be asking yourself or is there some food ingested that sparked off proceedings? Are there similar lesions appearing in & around your lips/oral cavity & is there a family history of any bleeding/blood disorder like say hereditary telangiectasia/purpuras?
Visiting a local large hospital & doing a few basic blood tests (CBC complete blood picture, BT/CT/PTT Bleeding time,clotting time & partial thromboplastin time) may help pinpoint the diagnosis & hence treatment. Cheers & Good luck. Do help this helps point you in the right direction. More often thatn not, it will resolve by itself but depending on the cause, symptomatic treatment may be in order eg for the jt pains/nausea etc..wish you a quick recovery & good health!

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