Viral exanthems in childhood. Part 3: Parainfectious exanthems and those associated with virus‐drug interactions

Abstract

Summary Viruses cause not only direct infectious exanthems, but also parainfectious exanthems, which provoke skin alterations via interactions with the immune system. These distinct exanthems, for instance Gianotti‐Crosti syndrome and pityriasis lichenoides group, do not reflect a specific pathogen but can occur in the course of many viral infections. In addition, some exanthems result from the interaction between viruses and drugs.

Amoxicillin‐induced generalized eruption associated with Epstein‐Barr virus reactivation in pregnancy

“…These features include onset of the eruption within a week of amoxicillin administration, copper‐colored generalized maculopapules with marked tendency for confluency resembling measles, absence of significant itching, and absence of desquamation on resolution. The eruption in our patient lacks features of a typical amoxicillin maculopapular eruption (allergic reaction), such as desquamation upon resolution, and is identical to previously described exanthems resulting from EBV–amoxicillin interaction; such exanthems have been reported in 10–29.5% of children and 70–100% of adults with florid EBV infection that were treated with amoxicillin or ampicillin. Possible pathogenetic mechanisms include a decreased immune tolerance in patients with IM or enhancement of immune reaction to the drug or its metabolites (EBV antibodies cross‐reacting with drug) .…”

“…The eruption in our patient lacks features of a typical amoxicillin maculopapular eruption (allergic reaction), such as desquamation upon resolution, and is identical to previously described exanthems resulting from EBV–amoxicillin interaction; such exanthems have been reported in 10–29.5% of children and 70–100% of adults with florid EBV infection that were treated with amoxicillin or ampicillin. Possible pathogenetic mechanisms include a decreased immune tolerance in patients with IM or enhancement of immune reaction to the drug or its metabolites (EBV antibodies cross‐reacting with drug) . However, a “true” amoxicillin allergy was demonstrated in a small percentage of these patients …”

“…The clinical features of our eruption are identical to those of the exanthem reported in patients with florid IM that received amoxicillin . These features include onset of the eruption within a week of amoxicillin administration, copper‐colored generalized maculopapules with marked tendency for confluency resembling measles, absence of significant itching, and absence of desquamation on resolution.…”

“…Amoxicillin–Epstein Barr Virus (EBV) interaction in patients with infectious mononucleosis (IM) can result in a generalized eruption . It has not been clarified whether such eruptions can occur in states that show high rates of EBV reactivation such as pregnancy …”

Characterizing Viral Exanthems

“…These include the nonpolio enteroviruses in the summer months, and rhinovirus, adenovirus, parainfluenza virus, respiratory syncytial virus and influenza virus in the winter [93]. The exanthem usually consists of erythematous macules and papules, but may be urticarial [94,95].…”