My Son , Age 3 , Was Diagnosed With Type

My son , age 3 , was diagnosed with type a flu dec 18 th, he ran low grade fever for about 3 days , was place on tamaflu for 5 days . On the fifth day I noticed a few red dots on torso and it has progressively worsened . The rash is o my on back , stomach , waist band , and shoulders . He is not fatigued , is not running a fever , and dose not have a cough now . When I initially took him , being diagnosed with he flu , I thought he had strep throat . Now his only complaint is legs hurting and feet hurting . He does no complain daily but has off and on for the past 3 weeks . Do you think the rash could be allergic reaction to tamaflu or from having the flu? What are your thoughts?