Paraviral exanthemaL42

Paraviral exanthema is a skin condition that can be interpreted as a response of the immune system to infections. Such reactions are also found in other infectious diseases as immunological responses to bacterial (bacterides) or mycotic (mycides) infections.

Major paraviral exanthemas that have been described as entities include:

• Gianotti-Crosti syndrome
• Pityriasis rosea
• Pityriasis lichenoides
• Papular-purpuric gloves and socks syndrome
• Asymmetric periflexural and unilateral mediothoracic exanthema
• Eruptive pseudoangiomatosis
• Eruptive hypomelanosis

In addition, there are forms of exanthema that can be understood as non-specific manifestations (virusides) of different types of viruses. Exemplary are multiforme exanthems which can occur after a multitude of viral (and non-viral) infections.

The skin manifestations of the classical viral exanthema diseases are triggered by viremia. Viruses can thus also be detected in the skin lesions.

Paraviral exanthema on the other hand are macromorphologically diverse. The detection of viruses in the skin is not possible. The skin lesions are self-limiting and thus can be classified as prognostically benign. They are not the expression of a specific pathogen but are induced by quite different viruses. The pathomechanism of this "réaction cutanée" is still unexplained.

1. Chuh A et al (2016) Pityriasis Rosea, Gianotti- Crosti Syndrome, Asymmetric Periflexural Exanthema, Papular-Purpuric Gloves and Socks Syndrome, Eruptive Pseudoangiomatosis, and Eruptive Hypomelanosis: Do Their Epidemiological Data Substantiate Infectious Etiologies? Infect Dis Rep 8:6418.
2. Chuh A et al (2017) Annular Eruptive Pseudoangiomatosis and Adenovirus Infection: A Novel Clinical Variant of Paraviral Exanthems and a Novel Virus Association. Acta Derm Venereol 97:354-357.
3. Fölster-Holst R et al (2016) Paraviral exanthems. Expert Rev Anti-Infect Ther 14:601-611.
4. Joseph RH et al (2015) Erythema multiforme after orf virus infection: a report of two cases and literature review. Epidemiol Infect 143:385-390