Pimply rash, swollen ears and fatigue

Patient: Hello.Two days ago, after a shower I broke out all over my torso. The skin was back to normal after several minutes, but some rash remained (pimply, with whiteheads) on my neck and shoulders and my ears are a bit swollen. I also feel slight fatigue, and pressure in the eyes (as if I have a small fever).I visited a doctor, who gave me some antihistamins, and said it would pass in a matter of days, claiming it is mostly some sort of viral infection.Could it be allergic reaction after all, or should I just wait and see?Thank you so much.

Doctor: