I used to go through this with difficult child 1 and difficult child 2. Both of them refused to shower, get in the tub, brush their teeth, comb their hair, etc., etc., etc. When difficult child 1 got home from day camp, he would go through the trouble of running the water in the shower, staying in the bathroom long enough so he would think I thought he bathed, change his clothes, head straight for his room and his computer. Even with clean clothes, he still smelled, his hair was dry, greasy, and he still was covered in dirt. Once I asked him why his hair was dry. He told me it dries very quickly. Right, and I just won megabucks, lol... difficult child 2 would get into the shower and come out looking much like difficult child 1 with the addition of food all over his face. I used to go through HE77 trying to get them to bathe!! Sorry you have the same problem with kiddo. Hugs, SFR
P.S. As soon as difficult child 1 became seriously interested in girls, we couldn't get him out of the shower. We had to threaten to remove his computer to get him to budge. Once he was out, he smelled like he dumped an entire bottle of cheap aftershave all over himself - Honestly, I don't know which was worse, lol...
P.S.S. Hope kiddo is feeling better today!!