Viral exanthemhttps://en.wikipedia.org/wiki/Exanthem
Viral exanthem is a widespread rash occurring on the outside of the body and usually occurring in children. An exanthem can be caused by toxins, drugs, or microorganisms, or can result from autoimmune disease. Many common viruses can produce a rash as part of their symptom. Varicella zoster virus (chickenpox or shingles) and mumps should be checked for the treatment.

○ Treatment ― OTC Drugs
OTC antihistamines may help with rashes and itching.
#Cetirizine [Zytec]
#Diphenhydramine [Benadryl]
#LevoCetirizine [Xyzal]
#Fexofenadine [Allegra]
#Loratadine [Claritin]
  • Rash of rubella on the skin of a child's back.
  • A rash appears all over the body. In most cases, there is no itching. There may or may not be a fever. Symptoms will be observed for 1 to 2 weeks while taking antihistamines.
References Viral exanthems 12952751
Eruptive pseudoangiomatosis, Erythema infectiosum and parvovirus B19, Gianotti-Crosti syndrome (papular acrodermatitis of childhood), Hand-foot-mouth disease, Herpangina, Measles (rubeola), Papular-purpuric gloves and socks syndrome, Pityriasis rosea, Roseola infantum (exanthem subitum), Rubella (German or 3-day measles), Unilateral laterothoracic exanthem (asymmetric periflexural exanthem of childhood)