The most common virus that causes orchitis is mumps. It most often occurs in boys after puberty. Orchitis most often develops 4 to 6 days after ...YouAreHere:Home→MedicalEncyclopedia→OrchitisURLofthispage://medlineplus.gov/ency/article/001280.htmOrchitisOrchitisisswelling(inflammation)ofoneorbothofthetesticles.CausesOrchitismaybecausedbyaninfection.Manytypesofbacteriaandvirusescancausethiscondition.Themostcommonvirusthatcausesorchitisismumps.Itmostoftenoccursinboysafterpuberty.Orchitismostoftendevelops4to6daysafterthemumpsbegins.Orchitismayalsooccuralongwithinfectionsoftheprostateorepididymis.Orchitismaybecausedbyasexuallytransmittedinfection(STI),suchasgonorrheaorchlamydia.Therateofsexuallytransmittedorchitisorepididymitisishigherinmenages19to35.Riskfactorsforsexuallytransmittedorchitisinclude:High-risksexualbehaviorsMultiplesexualpartnersPersonalhistoryofgonorrheaoranotherSTISexualpartnerwithadiagnosedSTIRiskfactorsfororchitisnotduetoanSTIinclude:Beingolderthanage45Long-termuseofaFoleycatheterNotbeingvaccinatedagainstthemumpsProblemsoftheurinarytractthatwerepresentatbirth(congenital)RepeatedurinarytractinfectionsSurgeryoftheurinarytract(genitourinarysurgery)BPH(benignprostatichyperplasia)-enlargedprostateUrethralstricture(scarringinsideurinarytract)SymptomsSymptomsinclude:PaininthetesticleBloodinthesemenDischargefrompenisFeverGroinpainPainwithintercourseorejaculationPainwithurination(dysuria)ScrotalswellingTender,swollengroinareaonaffectedsideTender,swollen,heavyfeelinginthetesticleExamsandTestsAphysicalexammayshow:EnlargedortenderprostateglandTenderandenlargedlymphnodesinthegroin(inguinal)areaontheaffectedsideTenderandenlargedtesticleontheaffectedsideRednessortendernessofscrotumTestsmayinclude:Completebloodcount(CBC)TesticularultrasoundTeststoscreenforchlamydiaandgonorrhea(urethralsmear)UrinalysisUrineculture(cleancatch)--mayneedseveralsamples,includinginitialstream,midstream,andafterprostatemassageTreatmentTreatmentmayinclude:Antibiotics,iftheinfectioniscausedby