Is it possible that the rash has returned after the end of antibiotic therapy?

Analyzing your statement, the case of your son is complex. Suspicion of scarlet fever followed by allergy to antibiotics is a case for outpatient/hospital treatment. Unfortunately, on the basis of photos, no pharmacist is able to make a diagnosis or diagnosis. That's what doctors are for. Has the child previously taken a similar antibiotic to Amotaks (Amoxicillin)? From a pharmacological point of view, beta-lactam antibiotics very often cause allergy not only in children, but also in adults. After treatment, the rash should gradually subside. Such a rash does itch, but it is up to the doctor to look at the exact structure of the rash and conduct an additional interview to diagnose what the child actually is. As for the length of antibiotic treatment. It is the doctor who decides on the length of therapy based on his experience, knowledge or guidelines. If it is not possible to visit a doctor and possibly consult another specialist, I encourage you to use the teleadvice offered, m.in. by the Gdziepolek.pl portal: https://www.gdziepolek.pl/telekonsultacja Article on scarlet fever: https://www.gdziepolek.pl/artykuly/szkarlatyna-wysypka-i-malinowy-jezyk

Well, it seemed to me that too short. On the second day the rash was worse. The family doctor referred us to the hospital, there again they told us that it was an allergy after an antibiotic . The son got an intramuscular injection and desensitizing drops improvement should be after the 3rd day . My friend again claims that it is mononucleosis. I read that mononucleosis does not itch and my son this rash itches slightly.