Definition
A viral exanthema is a skin rash caused by an infection with a viral pathogen. It appears reddened, usually does not itch and has a uniform appearance. A distinction is made between infectious and parainfectious viral exanthema, depending on whether one or more pathogens are involved in the development. Accompanying symptoms are often swollen lymph nodes and reddened mucous membranes. The exanthema occurs more frequently in childhood.
Cause of a virus exanthema
A viral exanthema occurs particularly in young children. Therefore, the causative viruses are predominantly viral pathogens relevant in childhood. Among the pathogens are e.g. the pathogens of measles, mumps, rubella, rubella (parvovirus B19), hand-foot-mouth disease (Coxsacki virus A16) and rotaviruses.
From the group of herpes viruses, the causative agents of chicken pox (varicella zoster virus), three-day fever (human herpes virus 6 and 7, HHV 6 and 7) and herpes simplex viruses, which cause herpes on the lips, among other things, are to be mentioned as causes of viral exanthema. Furthermore, Epstein-Barr viruses (Pfeiffer’s glandular fever) and hepatitis B viruses (Gianotti-Crosti syndrome) can trigger the development of an exanthema. A rarer cause is the dengue virus, which can cause the so-called dengue fever, especially in travel returnees from Central Africa and South America. If a virus-related exanthema occurs, one should always consider a fresh HIV infection and a corresponding examination and diagnosis should be carried out.
Associated symptoms
The symptoms of different virus exanthema can be manifold. What they have in common, however, is that they are almost always accompanied by fever and do not itch. Early symptoms of a cold as well as a general feeling of illness can also point the way forward.
There is also an accompanying swelling of the lymph nodes. A viral exanthema often occurs initially on the head and then spreads over the face and neck, sometimes over the entire body. This distinguishes the viral exanthema from a rash caused by certain drugs.
It usually starts at the trunk of the body (abdomen, chest, back), then spreads over the whole body and often itches the affected person. A typical trigger is e.g. penicillin. An exception, however, is the exanthema in the context of the viral Gianotti-Crosti syndrome, in which the rash appears not only on the head but also on the legs and buttocks.
